The windows-based software, called CrystalSleuth, may become an useful tool for analyzing and interpreting Raman spectra and powder X-ray diffraction data. The software may be able to compare multiple spectra and identify an unknown sample utilizing the online RRUFF project database.
With the continued technological advances portable Raman spectrophotometer may become even smaller and affordable in the future for gemological studies or other applications. This, combined with the free CrystalSlueth software may become a user-friendly tool for practising gemologist and gem dealers.
Raman spectral library is freely downloadable from the RRUFF Project web site @
http://rruff.info/about/about_software.php
Tuesday, May 15, 2007
Trapiche Tourmaline From Zambia
Well formed crystals of green tourmaline have been found with a growth pattern similar to trapiche emerald and ruby from Kavungu mine in the vicinity of Jivunda in Chief Sailunga's area, southeast of Mwinilunga in northwestern Zambia. Those who are not familiar with the crystal specimens may confuse for emeralds because of its color and patterns. The experts believe that the trapiche-like appearance may be due to skeletal growth with black carbonaceous substance, most likely being graphite, that may have been embedded with other impurities during the growth of the crystals. Chemical analysis indicate that the tourmaline is uvite and is colored green by vanadium. Facet quality specimens are rare due to the dark color of the tourmaline.
GemQ
when you are curious
ask this
simple question
what are gemstones?
where do they
come from?
why are some
stones so expensive?
why do people
go the extra mile
to find them?
the gemstones
speaks to you
in colorful languages
the mineral way
the gemstone way
gemstones are synonym
for love and status
symbol of commitment
intended gifts for a few
gemstones have
special status in
our culture
it is based on
an illusion
a few gems appreciate
value with time
some believe
gemstones are nature’s
gift to mankind
some believe they
are from the gods
of this universe
some believe they
are for the people
by the people
to share and enjoy
rarity and beauty
ask this
simple question
what are gemstones?
where do they
come from?
why are some
stones so expensive?
why do people
go the extra mile
to find them?
the gemstones
speaks to you
in colorful languages
the mineral way
the gemstone way
gemstones are synonym
for love and status
symbol of commitment
intended gifts for a few
gemstones have
special status in
our culture
it is based on
an illusion
a few gems appreciate
value with time
some believe
gemstones are nature’s
gift to mankind
some believe they
are from the gods
of this universe
some believe they
are for the people
by the people
to share and enjoy
rarity and beauty
Monday, May 14, 2007
Harper
Memorable quote from the movie:
Lew Archer (Paul Newman): The bottom is loaded with nice people, Albert. Only cream and bastards rise.
Lew Archer (Paul Newman): The bottom is loaded with nice people, Albert. Only cream and bastards rise.
His Jewellery Box
(via Live Mint) Parizaad Khan writes:
From pendants to gold bracelets and lapel pins, men’s fashion focuses on accents
As an architect, it’s a given that Jimmy Mistry, 34, pays attention to detail. But he takes it a step further when it comes to grooming. He spends a fair amount of time each morning coordinating his jewellery and accessories. So, apart from his white topaz and white gold ring (“very unobtrusive, it goes with both formals and informals”), he pairs a thin gold Italian bracelet with his steel Rolex, or matches his blue leather strap Audemars Piguet with a blue lacquer and steel pen. He’s figured out various other combinations, which he changes daily.
Mistry is a member of that group of men who were not scarred for life by Bappi Lahiri, so wearing jewellery doesn’t put him off. “I’m fond of accessories and like expressing myself this way.” His tip: “Stick to what you can carry off. I wouldn’t try a diamond pendant, though it looks good on Vijay Mallya,” he says.
Jewellery for men is no longer restricted to stones recommended by astrologers, gold chains or cuff links. It now includes materials like wood, steel, leather, semi-precious stones and even square-cut diamonds, as accents.
“All men are closet jewellery lovers,” believes Mumbai-based jewellery designer Anita Vaswani. “From the Zegna-wearing guys to metrosexuals—they all love embellishment,” she says. She’s currently working on a men’s line for her label, Stoned. Vaswani’s male friends keep demanding more, so the idea for an all-male line was born. But it’s not for the faint-hearted: hunks of turquoise and charms strung with Rudraksh beads.
On the other hand, Bollywood’s favourite designer, Farah Khan, has sobered up when it comes to sketching for the boys. She launched her male line last year, after asking corporate and film friends for inputs. “I found that most men weren’t afraid to experiment, but they like to keep it masculine, with geometric shapes or straight lines,” she says. She says her men’s line was a success because the timing was right. “Maybe it wouldn’t have been successful five years ago. It used to be macho not to wear jewellery, but now it is,” she says.
Khan isn’t off the mark. When Manali Vengsarkar, jewellery designer and cricketer Dilip Vengsarkar’s wife, launched her collection earlier this year, she presented the Indian cricket team with a long, tablet-shaped pendant strung with a leather thong. They were well received, so Vengsarkar’s men’s line will be launched before Diwali this year.
One of Vaswani’s clients is 31-year-old restaurateur Aditya Kilachand. He believes the days of gold chains are passé; today’s trend is to wear one statement piece, be it around the neck or wrist. Whether he’s working at his South Mumbai restaurant, Tetsuma, or partying with friends, he puts on three or four thin Rudraksh bracelets. “I like to leave my jewellery on all the time, I don’t wear things I have to change too often,” he says.
Mistry says he prefers to change every day and he accessorizes mostly when he’s at work. “In the evenings, I try to be as casual as possible,” he says.
Biren Vaidya, jewellery designer of the Rose Group, designs for those who don’t believe in being casual. His male line, Rose by Bee Vee, has contemporary pendants and bracelets, crafted from rubber, wood and steel. But his speciality is the flower or bee-shaped diamond lapel pin, worn on the lapel of a jacket or a shirt collar. “It’s a more subtle statement for those times when you can’t leave your shirt buttons open and wear a pendant. It always gets noticed and appreciated,” Vaidya says.
More info @ http://www.livemint.com/2007/05/12000525/His-jewellery-box.html
From pendants to gold bracelets and lapel pins, men’s fashion focuses on accents
As an architect, it’s a given that Jimmy Mistry, 34, pays attention to detail. But he takes it a step further when it comes to grooming. He spends a fair amount of time each morning coordinating his jewellery and accessories. So, apart from his white topaz and white gold ring (“very unobtrusive, it goes with both formals and informals”), he pairs a thin gold Italian bracelet with his steel Rolex, or matches his blue leather strap Audemars Piguet with a blue lacquer and steel pen. He’s figured out various other combinations, which he changes daily.
Mistry is a member of that group of men who were not scarred for life by Bappi Lahiri, so wearing jewellery doesn’t put him off. “I’m fond of accessories and like expressing myself this way.” His tip: “Stick to what you can carry off. I wouldn’t try a diamond pendant, though it looks good on Vijay Mallya,” he says.
Jewellery for men is no longer restricted to stones recommended by astrologers, gold chains or cuff links. It now includes materials like wood, steel, leather, semi-precious stones and even square-cut diamonds, as accents.
“All men are closet jewellery lovers,” believes Mumbai-based jewellery designer Anita Vaswani. “From the Zegna-wearing guys to metrosexuals—they all love embellishment,” she says. She’s currently working on a men’s line for her label, Stoned. Vaswani’s male friends keep demanding more, so the idea for an all-male line was born. But it’s not for the faint-hearted: hunks of turquoise and charms strung with Rudraksh beads.
On the other hand, Bollywood’s favourite designer, Farah Khan, has sobered up when it comes to sketching for the boys. She launched her male line last year, after asking corporate and film friends for inputs. “I found that most men weren’t afraid to experiment, but they like to keep it masculine, with geometric shapes or straight lines,” she says. She says her men’s line was a success because the timing was right. “Maybe it wouldn’t have been successful five years ago. It used to be macho not to wear jewellery, but now it is,” she says.
Khan isn’t off the mark. When Manali Vengsarkar, jewellery designer and cricketer Dilip Vengsarkar’s wife, launched her collection earlier this year, she presented the Indian cricket team with a long, tablet-shaped pendant strung with a leather thong. They were well received, so Vengsarkar’s men’s line will be launched before Diwali this year.
One of Vaswani’s clients is 31-year-old restaurateur Aditya Kilachand. He believes the days of gold chains are passé; today’s trend is to wear one statement piece, be it around the neck or wrist. Whether he’s working at his South Mumbai restaurant, Tetsuma, or partying with friends, he puts on three or four thin Rudraksh bracelets. “I like to leave my jewellery on all the time, I don’t wear things I have to change too often,” he says.
Mistry says he prefers to change every day and he accessorizes mostly when he’s at work. “In the evenings, I try to be as casual as possible,” he says.
Biren Vaidya, jewellery designer of the Rose Group, designs for those who don’t believe in being casual. His male line, Rose by Bee Vee, has contemporary pendants and bracelets, crafted from rubber, wood and steel. But his speciality is the flower or bee-shaped diamond lapel pin, worn on the lapel of a jacket or a shirt collar. “It’s a more subtle statement for those times when you can’t leave your shirt buttons open and wear a pendant. It always gets noticed and appreciated,” Vaidya says.
More info @ http://www.livemint.com/2007/05/12000525/His-jewellery-box.html
A Primer On Life Skills
2007: I think gemological schools should train their graduates on a similar wavelength. Many students lack soft skills, life skills and are totally clueless + unemployable. All they want is money, money, and plenty of money.
(via Business Standard) Prakash Iyer writes:
It was the summer of ’86. And as I, and the rest of the graduating batch, walked out of the hallowed portals of WIMWI (ah, the Well-known Institute of Management in Western India), you could sense that we were probably echoing Bryan Adams’ words as we looked back on our two years on campus: Indeed, those were the best days of my life!
We learnt the fundamentals of management. We learnt to draw up business plans, and evaluate advertising, and discount cash flows. More important, we learnt to stretch ourselves, and structure our thinking. We learnt to work hard. To compete. To win. And we made friends!
B-schools do a terrific job of equipping us with business skills. What’s missing, perhaps, is a primer on life skills. We emerge competent to deal with the complexities of running a business — but not quite as adept at managing the business of running our own lives.
Here then, in no particular order, are four life skills I wish they had taught us in B-school.
Goal setting: I wish every student passing out of B-school would walk out with a set of written goals for himself. A set of goals that define what each of us want to do, be, have and achieve. That would include financial and career goals for sure, but would also cover other key areas such as family, health, relationships and personal interests. Goals provide direction and discipline, helping us stay focused on what is really important to us. Without those goals, we tend to drift — and wonder why we sense a strange emptiness even as the next promotion beckons. And as the saying goes, if you don’t know where you are going, any road will take you there.
Communication: The best ideas and thought are of little use if we don’t learn to communicate them effectively. Learning to use the right words at the right time, to empathise and listen are priceless skills no one teaches us. We master an assortment of financial ratios but forget the message God sent us when he gave us two ears and one mouth: listen more than you speak. And making presentations is a key part of business life — yet you find bright young managers fidgeting nervously and reading out every word of a text-heavy and hastily prepared PowerPoint slide. If only they had been taught communication and presentation skills!
Good health: Corporate waistlines are expanding almost as rapidly as company bottom lines. And between early morning flights and late night conference calls, no one seems to have the time to take care of their own bodies. The games we grew up playing become the stuff we watch on TV. And our idea of a long walk is the trek from the corner room to the elevator. Perhaps B-schools should inculcate the habit of an hour in the gym every day. And the pursuit of a sport, say, every week.
Work-life balance: No man on his death-bed ever said “I wish I’d spent more time in the office.” Watching your child grow up, spending time with loved ones, being there at those special moments in other people’s lives — all these can probably give you as much joy as a deal clinched or a market share point gained.
“What would you do differently if you knew you had only six months to live?” We could all probably answer that one quite easily (spend more time with the family, play with the kids, take off on that vacation to the hills, write that book …). Alas, none of us really knows when precisely we have only six months to go.
B-schools teach us how to become change agents. We learn how to change the world, the consumer, the organisation, the works. But we don’t quite learn how to change one key piece: ourselves. Learning to change ourselves, our thoughts, our beliefs, and our actions can often be the biggest and most effective change we can make!
Prakash Iyer graduated from the Indian Institute of Management, Ahmedabad in 1986
More info @
http://www.businessstandard.com/common/storypage_supp.phpautono=283680&leftnm=1&subLeft=0&chkFlg=B-schools
(via Business Standard) Prakash Iyer writes:
It was the summer of ’86. And as I, and the rest of the graduating batch, walked out of the hallowed portals of WIMWI (ah, the Well-known Institute of Management in Western India), you could sense that we were probably echoing Bryan Adams’ words as we looked back on our two years on campus: Indeed, those were the best days of my life!
We learnt the fundamentals of management. We learnt to draw up business plans, and evaluate advertising, and discount cash flows. More important, we learnt to stretch ourselves, and structure our thinking. We learnt to work hard. To compete. To win. And we made friends!
B-schools do a terrific job of equipping us with business skills. What’s missing, perhaps, is a primer on life skills. We emerge competent to deal with the complexities of running a business — but not quite as adept at managing the business of running our own lives.
Here then, in no particular order, are four life skills I wish they had taught us in B-school.
Goal setting: I wish every student passing out of B-school would walk out with a set of written goals for himself. A set of goals that define what each of us want to do, be, have and achieve. That would include financial and career goals for sure, but would also cover other key areas such as family, health, relationships and personal interests. Goals provide direction and discipline, helping us stay focused on what is really important to us. Without those goals, we tend to drift — and wonder why we sense a strange emptiness even as the next promotion beckons. And as the saying goes, if you don’t know where you are going, any road will take you there.
Communication: The best ideas and thought are of little use if we don’t learn to communicate them effectively. Learning to use the right words at the right time, to empathise and listen are priceless skills no one teaches us. We master an assortment of financial ratios but forget the message God sent us when he gave us two ears and one mouth: listen more than you speak. And making presentations is a key part of business life — yet you find bright young managers fidgeting nervously and reading out every word of a text-heavy and hastily prepared PowerPoint slide. If only they had been taught communication and presentation skills!
Good health: Corporate waistlines are expanding almost as rapidly as company bottom lines. And between early morning flights and late night conference calls, no one seems to have the time to take care of their own bodies. The games we grew up playing become the stuff we watch on TV. And our idea of a long walk is the trek from the corner room to the elevator. Perhaps B-schools should inculcate the habit of an hour in the gym every day. And the pursuit of a sport, say, every week.
Work-life balance: No man on his death-bed ever said “I wish I’d spent more time in the office.” Watching your child grow up, spending time with loved ones, being there at those special moments in other people’s lives — all these can probably give you as much joy as a deal clinched or a market share point gained.
“What would you do differently if you knew you had only six months to live?” We could all probably answer that one quite easily (spend more time with the family, play with the kids, take off on that vacation to the hills, write that book …). Alas, none of us really knows when precisely we have only six months to go.
B-schools teach us how to become change agents. We learn how to change the world, the consumer, the organisation, the works. But we don’t quite learn how to change one key piece: ourselves. Learning to change ourselves, our thoughts, our beliefs, and our actions can often be the biggest and most effective change we can make!
Prakash Iyer graduated from the Indian Institute of Management, Ahmedabad in 1986
More info @
http://www.businessstandard.com/common/storypage_supp.phpautono=283680&leftnm=1&subLeft=0&chkFlg=B-schools
Identifying Opal Doublets
(via Gemological Digest, Vol.2, No.4, 1989) Grahame Brown writes:
Abstract
Opal doublets have in the past been produced mainly to utilize material otherwise too thin for cutting solids. They were not normally produced for fraudulent purposes, and identification was simple, due to an even join between opal and backing. Today, a new and more sinister type of opal doublet has appeared. Produced by bonding a rock backing to an irregular piece of precious opal, the result is a stone which looks very much like Queensland boulder opal, even to the trained eye.
In this article, the author discusses both the history of opal doublets, as well as the latest incarnations, and describes useful techniques for recognizing these frauds.
Introduction
The opal doublet is a cabochon-cut composite stone. It consists of two components: a domed ro flattened top of precious opal and a base of dark colored, light-absorbing material.
While natural opal doublets can be cut from some precious opal that occurs as near parallel layers of either opal potch, opal-ironstone, -sandstone, or –mudstone, most commercially marketed opal doublets are manufactured products that have been deliberately assembled, preformed and polished by man.
Origin
Available evidence suggests that the assembled opal doublet of Australian origin. It was first devised and manufactured in 1897 by miner-lapidaries on the remote, arid north-west New South Wales opal field of White Cliffs, 1000 km north-west of Sydney. The reason why these 19th century opal miners chose to manufacture the opal doublet was one of simple economics: only about 5 percent of the production output at White Cliffs was gem quality white opal. So, a use had to be found for the many thin veins of precious opal that could not be used for cutting solid opal cabochons. The opal doublet, made by cementing a thin layer of precious opal to a backing of dark grey opaque potch, was the simple, yet economic, answer to the low yield of precious solid opal from the White Cliffs field.
Method of manufacture
Today, opal doublets are commercially made for at least three reasons. First, the mined precious opal may be too thin to cut a solid opal. Second, the opal may have such a pale body color that its play-of-color (and value) could be enhanced by backing it with a suitable dark colored light absorbing material. Finally, by adhering a suitable backing to a thin layer of opal, the resulting composite could then be used to imitate opal of much greater value and rarity.
Choice of opal
Opals suitable for doublet manufacture should display the following characteristics:
- Freedom from clearly visible flaws (cracks, crazing, webbing, sand or gypsum inclusions, unsightly potch bars).
- A reasonable transparency, allowing light to penetrate through the opal top to the light absorbing backing.
- A distinct and rather muted play-of-color. This play-of-color is enhanced by being strongly contrasted against the dark backing.
- Sufficient thickness of precious opal to allow a flat plane-of-attachment to exist between the precious opal top and the light absorbing backing.
Consequently, flatish fragments of white or other pale-colored jelly or crystal opal make the most striking opal doublets. The use of opaque whitish to grayish opal only creates dull, lifeless doublets that display a poor play-of-color.
Choice of backing
The best backing for opal doublets is opaque black potch from Lightning Ridge. Due to the rarity of Lightning Ridge black potch, other opaque black backings, such as black glass, black plastic, obsidian, and even black onyx have been used to produce opal doublets imitating black opal. Care should be taken when choosing black backings for opal doublets: a backing with a coefficient-of-expansion differing from that of precious opal (e.g. black onyx) could fracture the doublet if moderate heat is applied to the finished composite.
With increased demand for dark Queensland boulder opal as an alternative for the increasingly rare and valuable Lightning Ridge black opal, manufacturers have begun producing opal doublets intended to imitate Queensland boulder opal. The precious opal component of these doublets may consist of thin, flat segments of Queensland boulder opal, whitish crystal opal shell pseudomorphs from Andamooka (South Australia), translucent to transparent whitish opal from Coober Pedy, Mintabie (South Australia) or White Cliffs (NSW). Backing for these doublets includes ironstone, dark-colored sandstone, and mudstone, commonly associated with Queensland boulder opal. There exists also a composite backing made by incorporating crushed fragments of the above materials into a black pigmented epoxy resin plastic.
A black backing is unnecessary when a doublet is made only to provide thickness and strength to a thin sliver of precious opal displaying a valuable color pattern. In such cases, grey potch, plastic or glass usually suffices as suitable backing.
Choice of adhesives
To permanently affix the top and backing of an opal doublet, most manufacturers use an epoxy-resin adhesive that is pigmented by carbon. Setting times of these adhesives vary from 5 minutes to 24 hours.
Methods of identification
Conventional opal doublets are identified traditionally by observing the presence of:
- Three components: a top of precious, natural opal; a backing of dark colored potch opal, glass, plastic, ironstone, sandstone, mudstone or iron stone filled black epoxy resin; a thin layer of adhesive permanently joining the top to the backing of the cabochon.
- A flat, junction-plane between the precious opal cabochon top and backing. This junction can vary in thickness. It often has gas bubble inclusions entrapped in the adhesive.
- Included, somewhat squashed, bubbles within the junction-plane of the doublet. The visibility of these bubbles is increased when the epoxy resin is viewed through the transparent opal top with the aid of an intense fiber optic light source.
- Occasional evidence of a pigment layer used to darken the flat-ground undersurface of the precious opal top of the doublet.
- Evidence of lifting of the top of the doublet from its backing, if the components are poorly adhered.
It is more difficult to identify some of the recently manufactured doublets designed to imitate boulder opal. These imitations are characterized by:
- Very thin, non-planar junctions between the top and the backing of the doublet.
- Junctions that are relatively free of included bubbles within the epoxy resin.
- Backings that are cut from coarse-grained sandy Quilpie ironstone/sandstone, or dark fine-grained banded Winton mudstone. Some of these backings are also included by thin anastamosing veins of precious opal.
To differentiate these effective look-alikes from the natural Queensland boulder opal they imitate, gemologists must be prepared to examine closely the junction separating the two components of a suspect doublet. In particular, one should look for identifying visual characteristics of Queensland boulder opal, such as:
- An irregular epoxy resin-free junction between the precious opal top and the ironstone, sandstone, or mudstone base of the cabochon. No visual evidence of an adhesive bubble-included junction should be seen when this interface is examined through the natural top of the boulder opal cabochon. Fiber-optic illumination greatly assists a detailed examination of the junction of most opal doublets.
- Tongue-like projections of precious opal that penetrate the sedimentary rock base (matrix) of the cabochon.
- A cabochon base formed from dark colored sedimentary rock (sandstone, ironstone, mudstone) that does not contain black plastic matrix or included gas bubbles.
Conclusions
It is not difficult to identify conventional opal doublets, made by cementing with black epoxy resin a top of diaphanous light colored jelly or crystal opal to a backing of dark potch, glass, plastic, or sedimentary rock. A simple 10x hand lens should quickly disclose the tell-tale, uniformly thick planar junction that is a feature of these composite stones. Hand lens or low power microscopic examination of the junction of conventional opal doublets should reveal gas bubble inclusions and/or solid particulate fillers within its content of black epoxy resin adhesive.
It is somewhat challenging to distinguish cabochons of Queensland boulder opal from their newer-manufactured doublet imitations. This is because the adhesive-filled junction between the precious opal top and the ironstone, sandstone or mudstone backing of these doublets is extremely thin, highly irregular in profile, and is made much less conspicuous by incorporation of finely ground particulate matter in the black epoxy-resin adhesive filling the junction. Careful low power microscopic examination of the junction area is required to identify the distinctive features of this effective look-alike of Queensland boulder opal.
Abstract
Opal doublets have in the past been produced mainly to utilize material otherwise too thin for cutting solids. They were not normally produced for fraudulent purposes, and identification was simple, due to an even join between opal and backing. Today, a new and more sinister type of opal doublet has appeared. Produced by bonding a rock backing to an irregular piece of precious opal, the result is a stone which looks very much like Queensland boulder opal, even to the trained eye.
In this article, the author discusses both the history of opal doublets, as well as the latest incarnations, and describes useful techniques for recognizing these frauds.
Introduction
The opal doublet is a cabochon-cut composite stone. It consists of two components: a domed ro flattened top of precious opal and a base of dark colored, light-absorbing material.
While natural opal doublets can be cut from some precious opal that occurs as near parallel layers of either opal potch, opal-ironstone, -sandstone, or –mudstone, most commercially marketed opal doublets are manufactured products that have been deliberately assembled, preformed and polished by man.
Origin
Available evidence suggests that the assembled opal doublet of Australian origin. It was first devised and manufactured in 1897 by miner-lapidaries on the remote, arid north-west New South Wales opal field of White Cliffs, 1000 km north-west of Sydney. The reason why these 19th century opal miners chose to manufacture the opal doublet was one of simple economics: only about 5 percent of the production output at White Cliffs was gem quality white opal. So, a use had to be found for the many thin veins of precious opal that could not be used for cutting solid opal cabochons. The opal doublet, made by cementing a thin layer of precious opal to a backing of dark grey opaque potch, was the simple, yet economic, answer to the low yield of precious solid opal from the White Cliffs field.
Method of manufacture
Today, opal doublets are commercially made for at least three reasons. First, the mined precious opal may be too thin to cut a solid opal. Second, the opal may have such a pale body color that its play-of-color (and value) could be enhanced by backing it with a suitable dark colored light absorbing material. Finally, by adhering a suitable backing to a thin layer of opal, the resulting composite could then be used to imitate opal of much greater value and rarity.
Choice of opal
Opals suitable for doublet manufacture should display the following characteristics:
- Freedom from clearly visible flaws (cracks, crazing, webbing, sand or gypsum inclusions, unsightly potch bars).
- A reasonable transparency, allowing light to penetrate through the opal top to the light absorbing backing.
- A distinct and rather muted play-of-color. This play-of-color is enhanced by being strongly contrasted against the dark backing.
- Sufficient thickness of precious opal to allow a flat plane-of-attachment to exist between the precious opal top and the light absorbing backing.
Consequently, flatish fragments of white or other pale-colored jelly or crystal opal make the most striking opal doublets. The use of opaque whitish to grayish opal only creates dull, lifeless doublets that display a poor play-of-color.
Choice of backing
The best backing for opal doublets is opaque black potch from Lightning Ridge. Due to the rarity of Lightning Ridge black potch, other opaque black backings, such as black glass, black plastic, obsidian, and even black onyx have been used to produce opal doublets imitating black opal. Care should be taken when choosing black backings for opal doublets: a backing with a coefficient-of-expansion differing from that of precious opal (e.g. black onyx) could fracture the doublet if moderate heat is applied to the finished composite.
With increased demand for dark Queensland boulder opal as an alternative for the increasingly rare and valuable Lightning Ridge black opal, manufacturers have begun producing opal doublets intended to imitate Queensland boulder opal. The precious opal component of these doublets may consist of thin, flat segments of Queensland boulder opal, whitish crystal opal shell pseudomorphs from Andamooka (South Australia), translucent to transparent whitish opal from Coober Pedy, Mintabie (South Australia) or White Cliffs (NSW). Backing for these doublets includes ironstone, dark-colored sandstone, and mudstone, commonly associated with Queensland boulder opal. There exists also a composite backing made by incorporating crushed fragments of the above materials into a black pigmented epoxy resin plastic.
A black backing is unnecessary when a doublet is made only to provide thickness and strength to a thin sliver of precious opal displaying a valuable color pattern. In such cases, grey potch, plastic or glass usually suffices as suitable backing.
Choice of adhesives
To permanently affix the top and backing of an opal doublet, most manufacturers use an epoxy-resin adhesive that is pigmented by carbon. Setting times of these adhesives vary from 5 minutes to 24 hours.
Methods of identification
Conventional opal doublets are identified traditionally by observing the presence of:
- Three components: a top of precious, natural opal; a backing of dark colored potch opal, glass, plastic, ironstone, sandstone, mudstone or iron stone filled black epoxy resin; a thin layer of adhesive permanently joining the top to the backing of the cabochon.
- A flat, junction-plane between the precious opal cabochon top and backing. This junction can vary in thickness. It often has gas bubble inclusions entrapped in the adhesive.
- Included, somewhat squashed, bubbles within the junction-plane of the doublet. The visibility of these bubbles is increased when the epoxy resin is viewed through the transparent opal top with the aid of an intense fiber optic light source.
- Occasional evidence of a pigment layer used to darken the flat-ground undersurface of the precious opal top of the doublet.
- Evidence of lifting of the top of the doublet from its backing, if the components are poorly adhered.
It is more difficult to identify some of the recently manufactured doublets designed to imitate boulder opal. These imitations are characterized by:
- Very thin, non-planar junctions between the top and the backing of the doublet.
- Junctions that are relatively free of included bubbles within the epoxy resin.
- Backings that are cut from coarse-grained sandy Quilpie ironstone/sandstone, or dark fine-grained banded Winton mudstone. Some of these backings are also included by thin anastamosing veins of precious opal.
To differentiate these effective look-alikes from the natural Queensland boulder opal they imitate, gemologists must be prepared to examine closely the junction separating the two components of a suspect doublet. In particular, one should look for identifying visual characteristics of Queensland boulder opal, such as:
- An irregular epoxy resin-free junction between the precious opal top and the ironstone, sandstone, or mudstone base of the cabochon. No visual evidence of an adhesive bubble-included junction should be seen when this interface is examined through the natural top of the boulder opal cabochon. Fiber-optic illumination greatly assists a detailed examination of the junction of most opal doublets.
- Tongue-like projections of precious opal that penetrate the sedimentary rock base (matrix) of the cabochon.
- A cabochon base formed from dark colored sedimentary rock (sandstone, ironstone, mudstone) that does not contain black plastic matrix or included gas bubbles.
Conclusions
It is not difficult to identify conventional opal doublets, made by cementing with black epoxy resin a top of diaphanous light colored jelly or crystal opal to a backing of dark potch, glass, plastic, or sedimentary rock. A simple 10x hand lens should quickly disclose the tell-tale, uniformly thick planar junction that is a feature of these composite stones. Hand lens or low power microscopic examination of the junction of conventional opal doublets should reveal gas bubble inclusions and/or solid particulate fillers within its content of black epoxy resin adhesive.
It is somewhat challenging to distinguish cabochons of Queensland boulder opal from their newer-manufactured doublet imitations. This is because the adhesive-filled junction between the precious opal top and the ironstone, sandstone or mudstone backing of these doublets is extremely thin, highly irregular in profile, and is made much less conspicuous by incorporation of finely ground particulate matter in the black epoxy-resin adhesive filling the junction. Careful low power microscopic examination of the junction area is required to identify the distinctive features of this effective look-alike of Queensland boulder opal.
How Dr Williamson Nearly Missed Finding The Mwadui Diamond Pipe
2007: Here is a remarkable story of a diamond prospector of a different generation. This can happen even today.
(via Indiaqua 23 1979/4)
Unpalatable to Tanzanian pride as it must be it does seem as if the discovery of their greatest natural asset, diamonds, is owed to a combination of Irish independence and Canadian frustration. Irish because Dr John Thorburn Williamson was of that ancestory, and Canadian because logging n Quebec did not appeal to the future finder of the diamondiferous Mwadui diamond pipe.
It is also, it seems, a subject which an Italian called Signor Bondini prefers to dismiss as one consequence of Italian reverses in the last World War—since he was interned at the moment of his own discovery at Mwadui.
Mr G J du Toit’s unpublished manuscript states that Williamson “took to Geology by chance,” and obtained a B A degree with Honors. Post graduate work on Newfoundland minerals enabled him to achieve an M Sc degree in 1930, and subsequently a Ph D in 1933, as a result of a thesis on chromite. This work brought him to contact with the doyen of Canadian geologists, Dr Joe Bancroft, then Consulting Geologist to the fledgling Anglo American Corporation of S.A.Ltd. After a brief job with the Quebec Gold Mining Corp., Dr J T Williamson said au revoir to his family and sailed aboard the Italian liner “Rex” from New York to Cape Town.
On arrival at the Cape he took the Rhodesian Express to Bulawayo and joined the Bechuanaland Exploration Co Ltd being seconded to Loangwa Concessions (N.R) Ltd based at Rhodesia Broker Hill. It was here that he made a few small gold deposit discoveries 7 years later further north in Tanganyika. He also discovered that a little lime in a scotch and water took away the brackish taste.
Break with De Beers
Legend has it that Williamson fell out with the Anglo American Group in 1935 and he went doggedly on to trace diamonds in Tanzania. The truth is that he joined a company which was seeking a geologist—Tanganyika Diamond & Gold Development Ltd. This company operated three small diamond mines at Mabuki and Kizumbe near Shinyanga Plain, found in 1913 and 1926 respectively. The diamond content of these mines was not attractive. This puzzled Williamson who developed a theory that garnets and ilmenite found in diamondiferous deposits were quite different from garnets found without the presence of diamonds.
Unsatisfied with £55 per month Williamson left “Tanks” in 1938, and brought the Mabuki deposit for a few hundred pounds. He also acquired malaria and black water fever—and an Indian barrister’s interest, Mr I C Chopra, who called his new client “the gentleman from the bush.”
Following his geological hunches Dr Williamson began to take the lone prospector role seriously and one night he sat up all night in a truck waiting to peg his claim at dawn at Kizumbe. An Italian, Mr Bondini, in the vicinity, was also on the diamond trail, but he spent his nights more enjoyably in bed. Also more rewardingly, because by 1939 Williamson was in a mood to quit Tanganyika. He contemplated joining the military service, but before be could achieve that he had to pay various bills to Indian storekeepers. His German creditors had mostly been interned.
Somehow his debts to Indian storekeepers save him. He was able to retain only a few African prospectors and on 6th March 1940 James, son of Anton, brought on his truck to base camp a large piece of ilmenite from the village of Luhombo—from a trench actually dug by the Geological Survey of Tanganyika. Williamson looked deep and long at that ilmenite—often an associate of diamond. From the ilmenite a 2 carat diamond was extracted. And James was of that moment included in Williamson’s will—unbeknown to either men.
Enter and exit a Roman prospector
At dawn on 7th March Williamson drove hell for leather to the spot where James had picked up the ilmenite—a place called Mwadui, and then to the District Commisioner to apply, and obtain, an Exclusive Prospecting Licence. A few days later Williamson applied for claims as ‘discoverer”, to 3 square miles north-west of Luhumbo village, Mwadui. Who appeared at the District Commissioner’s office but the Italian, Signor Bondini, to protest on the grounds he was there first. He was dispatched in the most appropriate British manner by being arrested and subsequently interned as an alien. This seem sag geologically since Dr Williamson later acknowledged that the Italian was his chief rival and implied he knew a lot about Mwadui diamond deposits.
Williamson proceeded to peg with uncanny accuracy the limits of what turned out to be the world’s biggest diamondiferous pipe. To sisal and cotton were now to be added diamonds—Tangayika’s principal products. And to the fairly simple, pleasure-loving Dr Williamson diamonds found within his pegged area were to add a fiendish complexity. Prospecting revealed substantial diamond finds, which Williamson, trusting few, took personally to the Mwanza Branch of the Standard Bank. In Mwanza he took the opportunity to call on his lawyer, Mr I C Chopra. They discovered they shared an Irish heritage—for Chopra had gone to Dublin from Gurjanwala at eleven years of age before settling in East Africa 21 years later, where his intelligence and public spiritedness earned him the C.B.E…
Williamson becomes a limited company to Socialist acclaim
By 1942 Williamson Diamonds Ltd had been incorporated with a capital of £200000 (400 shared of £500 each), Chopra subscribing for 1, Williamson’s brother got 100 free and the doctor paid for the balance of 299. Williamson was running the show, even to the extent of listing the weight and number of diamonds recovered by sunset each day. He grew thin and irritable, not fat and prosperous in the capitalist tradition. By 1944 Dr Joe Bancroft of Anglo American was on the scene and on behalf of Sir Ernest Oppenheimer offered £2m to Williamson for outright control of the mine. Williamson refused. Thanks to Italian prisoners of war being employed on the mine, Williamson, who referred to them as “these industrious little men,” began to see that Williamson Diamonds Ltd had a major productive role to play on the diamond stage. This realization was simultaneously shared by Sir Ernest Oppenheimer in Johannesburg.
By 1946 the British Colonial Secretary Creech Jones had visited Mwadui and left convinced Williamson was almost a teetotaler and that nationalization of his mine would turn African people off socialist doctrine. So Williamson ran his mine roughly as he pleased. It was a boisterous era in which physical feats were socially applauded. Williamson would turn up nightly in European Club—seldom in the Asian or African counterpart. He also developed a penchant for Peter Scott bird studies of stormy seascapes as well as Russell Flint’s paintings.
The Williamson story
The mining industry does not relish loners. Teamwork is the catchword. But in the case of Canadian geologist Dr John Thorburn Williamson—the diamond industry accorded him a special respect, supreme loner that he was. Had he not only discovered but also owned an enormous diamond mine his name would possibly by now have been fairly well forgotten. But it is not forgotten and his story continues to stir many a geologist throughout the Western world as he takes his first tentative step into bush, desert, outback, or jungle.
For the following excerpts from Williamson’s last ten years Indiaqua is indebted to Mr Gabriel J du Toit, a South African mining man who for 10 years was closely associated with the ‘Doctor’ in the development of the Williamson Diamond Mine.
Part 1 in Indiaqua 9 described Dr J T Williamson’s origins, his start in Southern Africa, his break from De Beers and his amazing discovery in 1940 of the world’s biggest diamond pipe, 361 acres on the surface. By 1947 Dr John Williamson was feeling on top of the world. The price of diamonds was rising fast, the Williamson Mine diamonds were of high quality, and there were several hundred persons employed at Mwadui producing several thousand carats per month.
Bachelor status for man and mine
This called for a celebration and Dr Williamson, then aged, 44, flew south to Johannesburg, to recruit mining engineers and metallurgists, security experts and medical assistants for his mine. During his stay, contact was made with the Anglo American Corporation’s Geological Department. Their interest naturally centered on the dimensions and yield of the Mwadui diamond pipe. Dr Joe Bancroft, the doyen of Anglo American’s geologists, proposed a joint prospecting programme. This was linked with an offer to participate in the Williamson company, whereby the doctor would receive £750000. The loner’s instincts reacted and Williamson returned to the mine that bore his name—determined that it should continue to do so, without partners.
The next scare for Dr Williamson was the British Labor Party’s plan to nationalize the mine. Only a direct appeal to the Colonial Secretary, Mr Arthur Creech Jones, caused those plans to be shelved. This incident spurred Dr Williamson to redouble his efforts in exploring and developing the diamond mine. The fiasco of the British Government’s nationalized East African ground nut scheme would not be repeated with his diamonds. However, problems at the mine were not long in coming—security became a great headache, ‘over mining’ of rich areas was not appreciated by the Government mining inspectors, and for a brilliant geologist the revelation that the pipe contracted sharply—in fact at only 50 meters the 361 acres on the surface shrunk to a mere tenth, while at 75 meters deep the pipe had narrowed to a thin dyke—must have been deeply disappointing.
Dr Williamson disposed of the mine’s production of diamonds through the Diamond Corporation Ltd in London as a result of the agreement made in December 1947. The course of this contract did not run smoothly and at one time Williamson Diamonds Ltd received no revenue for 18 months because of disputes, arbitrations and misunderstandings that plagued the functioning of the agreement.
Dr Williamson succumbs
In 1956 Dr Williamson was found to have advanced cancer of the larynx. Distraught, he proceeded to Montreal to stay with his sister, Mrs Mary Miller. Depressed by the endless Canadian winter he flew to Australia to meet his friend Mr Albert Joris, who was shocked by his appearance. From Sydney Williamson journeyed to Japan, Hong Kong and Singapore in search of earth moving equipment. Then he decided to visit Johannesburg. Sir Ernest Oppenheimer sent his personal aide to the Langham Hotel suite to invite Williamson to Brenthurst, the Oppenheimer home. Dr Williamson declined.
Weighing only 100 lbs. the Doctor flew to Nairobi, and on to his beloved mine. With a scarf wrapped around his neck he would take rides at night around the mine, hiding from the eyes of thousands of his employees. On Jan 8th 1957, aged 50, Dr John Williamson died. Sir Ernest had died only a few weeks earlier in Johannesburg. Dr Williamson left all his assets to his family in Canada. He had never married. Shortly after Williamson’s death, Mr Harry Oppenheimer, in his first big deal, flew to Mwadui and successfully negotiated for the purchase by his group of 50% in Williamson Diamonds Ltd, the government of Tanganyika acquiring the other 50%.
His successor as Chairman of Williamson Diamonds Ltd was none other than Mr Harry Oppenheimer, until succeeded 15 years later by Mr Timothy Apiyo, Principal Secretary of the Tanzanian Ministry of Commerce & Industries. Mr George Hunt, who had been appointed General Manager in 1958, was replaced by Mr Samuel Lwakatare in 1973, who had obtained an M.Sc in engineering from Dr Williamson’s old McGill University, Montreal.
(via Indiaqua 23 1979/4)
Unpalatable to Tanzanian pride as it must be it does seem as if the discovery of their greatest natural asset, diamonds, is owed to a combination of Irish independence and Canadian frustration. Irish because Dr John Thorburn Williamson was of that ancestory, and Canadian because logging n Quebec did not appeal to the future finder of the diamondiferous Mwadui diamond pipe.
It is also, it seems, a subject which an Italian called Signor Bondini prefers to dismiss as one consequence of Italian reverses in the last World War—since he was interned at the moment of his own discovery at Mwadui.
Mr G J du Toit’s unpublished manuscript states that Williamson “took to Geology by chance,” and obtained a B A degree with Honors. Post graduate work on Newfoundland minerals enabled him to achieve an M Sc degree in 1930, and subsequently a Ph D in 1933, as a result of a thesis on chromite. This work brought him to contact with the doyen of Canadian geologists, Dr Joe Bancroft, then Consulting Geologist to the fledgling Anglo American Corporation of S.A.Ltd. After a brief job with the Quebec Gold Mining Corp., Dr J T Williamson said au revoir to his family and sailed aboard the Italian liner “Rex” from New York to Cape Town.
On arrival at the Cape he took the Rhodesian Express to Bulawayo and joined the Bechuanaland Exploration Co Ltd being seconded to Loangwa Concessions (N.R) Ltd based at Rhodesia Broker Hill. It was here that he made a few small gold deposit discoveries 7 years later further north in Tanganyika. He also discovered that a little lime in a scotch and water took away the brackish taste.
Break with De Beers
Legend has it that Williamson fell out with the Anglo American Group in 1935 and he went doggedly on to trace diamonds in Tanzania. The truth is that he joined a company which was seeking a geologist—Tanganyika Diamond & Gold Development Ltd. This company operated three small diamond mines at Mabuki and Kizumbe near Shinyanga Plain, found in 1913 and 1926 respectively. The diamond content of these mines was not attractive. This puzzled Williamson who developed a theory that garnets and ilmenite found in diamondiferous deposits were quite different from garnets found without the presence of diamonds.
Unsatisfied with £55 per month Williamson left “Tanks” in 1938, and brought the Mabuki deposit for a few hundred pounds. He also acquired malaria and black water fever—and an Indian barrister’s interest, Mr I C Chopra, who called his new client “the gentleman from the bush.”
Following his geological hunches Dr Williamson began to take the lone prospector role seriously and one night he sat up all night in a truck waiting to peg his claim at dawn at Kizumbe. An Italian, Mr Bondini, in the vicinity, was also on the diamond trail, but he spent his nights more enjoyably in bed. Also more rewardingly, because by 1939 Williamson was in a mood to quit Tanganyika. He contemplated joining the military service, but before be could achieve that he had to pay various bills to Indian storekeepers. His German creditors had mostly been interned.
Somehow his debts to Indian storekeepers save him. He was able to retain only a few African prospectors and on 6th March 1940 James, son of Anton, brought on his truck to base camp a large piece of ilmenite from the village of Luhombo—from a trench actually dug by the Geological Survey of Tanganyika. Williamson looked deep and long at that ilmenite—often an associate of diamond. From the ilmenite a 2 carat diamond was extracted. And James was of that moment included in Williamson’s will—unbeknown to either men.
Enter and exit a Roman prospector
At dawn on 7th March Williamson drove hell for leather to the spot where James had picked up the ilmenite—a place called Mwadui, and then to the District Commisioner to apply, and obtain, an Exclusive Prospecting Licence. A few days later Williamson applied for claims as ‘discoverer”, to 3 square miles north-west of Luhumbo village, Mwadui. Who appeared at the District Commissioner’s office but the Italian, Signor Bondini, to protest on the grounds he was there first. He was dispatched in the most appropriate British manner by being arrested and subsequently interned as an alien. This seem sag geologically since Dr Williamson later acknowledged that the Italian was his chief rival and implied he knew a lot about Mwadui diamond deposits.
Williamson proceeded to peg with uncanny accuracy the limits of what turned out to be the world’s biggest diamondiferous pipe. To sisal and cotton were now to be added diamonds—Tangayika’s principal products. And to the fairly simple, pleasure-loving Dr Williamson diamonds found within his pegged area were to add a fiendish complexity. Prospecting revealed substantial diamond finds, which Williamson, trusting few, took personally to the Mwanza Branch of the Standard Bank. In Mwanza he took the opportunity to call on his lawyer, Mr I C Chopra. They discovered they shared an Irish heritage—for Chopra had gone to Dublin from Gurjanwala at eleven years of age before settling in East Africa 21 years later, where his intelligence and public spiritedness earned him the C.B.E…
Williamson becomes a limited company to Socialist acclaim
By 1942 Williamson Diamonds Ltd had been incorporated with a capital of £200000 (400 shared of £500 each), Chopra subscribing for 1, Williamson’s brother got 100 free and the doctor paid for the balance of 299. Williamson was running the show, even to the extent of listing the weight and number of diamonds recovered by sunset each day. He grew thin and irritable, not fat and prosperous in the capitalist tradition. By 1944 Dr Joe Bancroft of Anglo American was on the scene and on behalf of Sir Ernest Oppenheimer offered £2m to Williamson for outright control of the mine. Williamson refused. Thanks to Italian prisoners of war being employed on the mine, Williamson, who referred to them as “these industrious little men,” began to see that Williamson Diamonds Ltd had a major productive role to play on the diamond stage. This realization was simultaneously shared by Sir Ernest Oppenheimer in Johannesburg.
By 1946 the British Colonial Secretary Creech Jones had visited Mwadui and left convinced Williamson was almost a teetotaler and that nationalization of his mine would turn African people off socialist doctrine. So Williamson ran his mine roughly as he pleased. It was a boisterous era in which physical feats were socially applauded. Williamson would turn up nightly in European Club—seldom in the Asian or African counterpart. He also developed a penchant for Peter Scott bird studies of stormy seascapes as well as Russell Flint’s paintings.
The Williamson story
The mining industry does not relish loners. Teamwork is the catchword. But in the case of Canadian geologist Dr John Thorburn Williamson—the diamond industry accorded him a special respect, supreme loner that he was. Had he not only discovered but also owned an enormous diamond mine his name would possibly by now have been fairly well forgotten. But it is not forgotten and his story continues to stir many a geologist throughout the Western world as he takes his first tentative step into bush, desert, outback, or jungle.
For the following excerpts from Williamson’s last ten years Indiaqua is indebted to Mr Gabriel J du Toit, a South African mining man who for 10 years was closely associated with the ‘Doctor’ in the development of the Williamson Diamond Mine.
Part 1 in Indiaqua 9 described Dr J T Williamson’s origins, his start in Southern Africa, his break from De Beers and his amazing discovery in 1940 of the world’s biggest diamond pipe, 361 acres on the surface. By 1947 Dr John Williamson was feeling on top of the world. The price of diamonds was rising fast, the Williamson Mine diamonds were of high quality, and there were several hundred persons employed at Mwadui producing several thousand carats per month.
Bachelor status for man and mine
This called for a celebration and Dr Williamson, then aged, 44, flew south to Johannesburg, to recruit mining engineers and metallurgists, security experts and medical assistants for his mine. During his stay, contact was made with the Anglo American Corporation’s Geological Department. Their interest naturally centered on the dimensions and yield of the Mwadui diamond pipe. Dr Joe Bancroft, the doyen of Anglo American’s geologists, proposed a joint prospecting programme. This was linked with an offer to participate in the Williamson company, whereby the doctor would receive £750000. The loner’s instincts reacted and Williamson returned to the mine that bore his name—determined that it should continue to do so, without partners.
The next scare for Dr Williamson was the British Labor Party’s plan to nationalize the mine. Only a direct appeal to the Colonial Secretary, Mr Arthur Creech Jones, caused those plans to be shelved. This incident spurred Dr Williamson to redouble his efforts in exploring and developing the diamond mine. The fiasco of the British Government’s nationalized East African ground nut scheme would not be repeated with his diamonds. However, problems at the mine were not long in coming—security became a great headache, ‘over mining’ of rich areas was not appreciated by the Government mining inspectors, and for a brilliant geologist the revelation that the pipe contracted sharply—in fact at only 50 meters the 361 acres on the surface shrunk to a mere tenth, while at 75 meters deep the pipe had narrowed to a thin dyke—must have been deeply disappointing.
Dr Williamson disposed of the mine’s production of diamonds through the Diamond Corporation Ltd in London as a result of the agreement made in December 1947. The course of this contract did not run smoothly and at one time Williamson Diamonds Ltd received no revenue for 18 months because of disputes, arbitrations and misunderstandings that plagued the functioning of the agreement.
Dr Williamson succumbs
In 1956 Dr Williamson was found to have advanced cancer of the larynx. Distraught, he proceeded to Montreal to stay with his sister, Mrs Mary Miller. Depressed by the endless Canadian winter he flew to Australia to meet his friend Mr Albert Joris, who was shocked by his appearance. From Sydney Williamson journeyed to Japan, Hong Kong and Singapore in search of earth moving equipment. Then he decided to visit Johannesburg. Sir Ernest Oppenheimer sent his personal aide to the Langham Hotel suite to invite Williamson to Brenthurst, the Oppenheimer home. Dr Williamson declined.
Weighing only 100 lbs. the Doctor flew to Nairobi, and on to his beloved mine. With a scarf wrapped around his neck he would take rides at night around the mine, hiding from the eyes of thousands of his employees. On Jan 8th 1957, aged 50, Dr John Williamson died. Sir Ernest had died only a few weeks earlier in Johannesburg. Dr Williamson left all his assets to his family in Canada. He had never married. Shortly after Williamson’s death, Mr Harry Oppenheimer, in his first big deal, flew to Mwadui and successfully negotiated for the purchase by his group of 50% in Williamson Diamonds Ltd, the government of Tanganyika acquiring the other 50%.
His successor as Chairman of Williamson Diamonds Ltd was none other than Mr Harry Oppenheimer, until succeeded 15 years later by Mr Timothy Apiyo, Principal Secretary of the Tanzanian Ministry of Commerce & Industries. Mr George Hunt, who had been appointed General Manager in 1958, was replaced by Mr Samuel Lwakatare in 1973, who had obtained an M.Sc in engineering from Dr Williamson’s old McGill University, Montreal.
Subscribe to:
Comments (Atom)