By Ali H Kazmi and L W Snee
Geological Survey of Pakistan
Van Nostrand Reinhold Company
1989 ISBN 0-442-30328-9
Van Nostrand Reinhold Company writes:
Emerald has been known to mankind since prehistoric times and yet is one of the rarest of gemstones—found only in a few locations. The uniqueness of emerald is a result of the unusual combination of two chemical elements, beryllium and chromium, that normally are not associated in nature. This special combination is controlled by fascinating geological processes that brought rocks of very different character together under conditions that permitted the formation of these beautiful green gems. Thus, emerald is not only fascinating to the gemologist and mineral collector because of its exceptional beauty but also to the geologist because of the geological process it represents.
Emeralds of Pakistan—geology, gemology, and genesis examines emeralds of Pakistan from three viewpoints—geologic, occurrence, physical and chemical characteristics of the gems, and origin. With scores of figures, including 81 color plates, the book describes and illustrates emeralds of Pakistan and summarizes the geologic occurrence of other worldwide emerald deposits.
Nine chapters and a selected bibliography summarize nearly ten years of research by 12 scientists. Emeralds of Pakistan—geology, gemology, and genesis covers such topics as:
- geology and tectonics of Pakistan
- geologic setting of Pakistan emeralds
- gemological characteristics of Pakistani emeralds
- comprehensive data on inclusions within the emeralds
- chemistry of the emeralds and their host rocks
- microprobe analyses of the emeralds
- geology of world emerald deposits
- origin of emeralds
- selected bibliography
This is the first book of its kind on the geology of emerald deposits of one area in the world. However, the book also presents the best current summary of all world emerald deposits and develops a new classification system for emerald deposits.
Thursday, February 08, 2007
Wednesday, February 07, 2007
Diffusion Treatment Of Natural And Synthetic Sapphire And Ruby
Corundum with sufficient titanium are good samples for the development of asterism (stars) by heat treatment. Asterism can be developed by diffusing titanium into the corundum crystal lattice with appropriate heat treatment apparatus. The technique is very similar to the production of asterism in Verneuil (flame fusion)-grown synthetic sapphires without titanium content. The technique is applied by many companies to produce stones with asterism (stars). In Thailand both natural, synthetic and treated stones are available.
The process consists of :
1. Diffusion treatment of corundum samples in mixture of aluminum oxide and titanium oxide powder. The temperatures required to facilitate the process (diffusing a thin surface layer) may be in the range of 1700 - 1950 degrees centigrade.
2. The samples are then heat treated in a temperature in the range of 1100 - 1500 degrees centigrade permitting the formation of rutile needles in the surface layer.
The asterism (stars) created by this two step process is caused by needles within only a thin surface layer. When properly done, the visual appearance of treated samples may look very similar to that of untreated natural stones.
With careful examination under the microscope + immersion technique (with sample stones: treated + untreated stones) most treated stones can be identified if they are unset (loose stones).
The process consists of :
1. Diffusion treatment of corundum samples in mixture of aluminum oxide and titanium oxide powder. The temperatures required to facilitate the process (diffusing a thin surface layer) may be in the range of 1700 - 1950 degrees centigrade.
2. The samples are then heat treated in a temperature in the range of 1100 - 1500 degrees centigrade permitting the formation of rutile needles in the surface layer.
The asterism (stars) created by this two step process is caused by needles within only a thin surface layer. When properly done, the visual appearance of treated samples may look very similar to that of untreated natural stones.
With careful examination under the microscope + immersion technique (with sample stones: treated + untreated stones) most treated stones can be identified if they are unset (loose stones).
Sting Movie
Memorable quote (s) from the movie:
J.J. Singleton (Ray Walston): I dunno know what to do with this guy, Henry. He's an Irishman who doesn't drink, doesn't smoke, and doesn't chase dames. He's a grand knight in the Knights of Columbus, and he only goes out to play faro. Sometimes plays 15 or 20 hours at a time, just him against the house.
Henry Gondorff (Paul Newman): Roulette? Craps?
J.J. Singleton (Ray Walston): He won't touch them. The croupier at Gilman's says he never plays anything he can't win.
Henry Gondorff (Paul Newman): Sports?
J.J. Singleton (Ray Walston): Likes to be seen with fighters sometimes, but he doesn't go to the fights or bet on them.
Henry Gondorff (Paul Newman): Jesus. Does he do anything where he's not alone?
J.J. Singleton (Ray Walston): Just poker. And he cheats. Pretty good at it, too.
J.J. Singleton (Ray Walston): I dunno know what to do with this guy, Henry. He's an Irishman who doesn't drink, doesn't smoke, and doesn't chase dames. He's a grand knight in the Knights of Columbus, and he only goes out to play faro. Sometimes plays 15 or 20 hours at a time, just him against the house.
Henry Gondorff (Paul Newman): Roulette? Craps?
J.J. Singleton (Ray Walston): He won't touch them. The croupier at Gilman's says he never plays anything he can't win.
Henry Gondorff (Paul Newman): Sports?
J.J. Singleton (Ray Walston): Likes to be seen with fighters sometimes, but he doesn't go to the fights or bet on them.
Henry Gondorff (Paul Newman): Jesus. Does he do anything where he's not alone?
J.J. Singleton (Ray Walston): Just poker. And he cheats. Pretty good at it, too.
Charles T Munger
One of my favourite quote from Charles Munger.
Charles T Munger, Vice-Chairman of Berkshire Hathaway Corporation writes:
"Never wrestle with a pig, for if you do, you will both get dirty, but the pig will enjoy it."
Charles T Munger, Vice-Chairman of Berkshire Hathaway Corporation writes:
"Never wrestle with a pig, for if you do, you will both get dirty, but the pig will enjoy it."
The Federal Trade Commission’s Guide for the Jewelry, Precious Metals and Pewter Industries
FTC writes:
23.13 Disclosure of treatments to diamonds.
A diamond is a gemstone product. Treatments to diamonds should be disclosed in the manner prescribed in 23.22 of these guides, Disclosure of treatments to gemstones.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
23.13 Disclosure of treatments to diamonds.
A diamond is a gemstone product. Treatments to diamonds should be disclosed in the manner prescribed in 23.22 of these guides, Disclosure of treatments to gemstones.
More info @ http://www.ftc.gov/bcp/guides/jewel-gd.htm
The Art Of Jewelry
By Graham Hughes
Studio Vista Publishers
Peerage Books
1972 ISBN 0-907408-30-3
Peerage Books writes:
When a precious stone becomes a jewel, a work of art has been created and a story has begun. In this book, Graham Hughes, Art Director of the Worshipful Company of Goldsmiths of the City of London, tells the story of jewelry—its history, its changing styles, its craftsmen and designers and their techniques, its great collectors and patrons, its discoverers, its value and allure.
He traces the evolution of jewelry style from pre-history to the 1970s, through the great civilizations of Egypt, Greece, Byzantium, Rome and pre-Columbian South America, down through the Dark Ages and medieval times to the Renaissance, the eighteenth century and modern times. Included in this survey are the treasures of Persia, the traveling riches of the barbarians, the abundant gold of Africa and the magnificent, uncountable wealth of India.
Graham Hughes suggests that jewelry may be the oldest art; the most ancient jewels from Ur, Assyria and Babylon, from Pharaonic Egypt, Minoan Crete and Mycenae are evidence that the craft’s basic techniques were already established and well practiced before history began its records. He examines the technique of jewelers: not only modern developments like centrifugal casting machines, but the patience and skill of Etruscan craftsmen who painstakingly affixed by hand tiny, individual granules of gold to create patterns and distinctive finishes. He considers the dominance of that most marvelous metal, gold, which has probably been the chief asset to jewelers everywhere at all times.
From the giant stores of Japan selling jewels by the thousands to the grand and well-known names of jewelry design and business, and the tiny workshops where one or maybe two craftsmen turn their ideas into works of art, Graham Hughes explores the impact of jewelry. He interviews the world’s leading artist-jewelers examining their lives, ideas, attitudes to their creations, and relations with their buying public.
He reminds us of the exiting discoveries of Schliemann, Carter, Sir Arthur Evans and others, who relocated hoards that had been lost for centuries, and takes us on a tour of the great jewelry collections—like the Tsarist treasures, the tears of all Russia—bemoaning the sad fate of jewels which lie in dead museum vaults instead of being worn as their creators intended.
The book ends with an examination of the value and meaning of jewels to different ages of mankind, raising some fascinating questions. Why, for instance, is a Gilson cultured emerald scorned and deemed worthless when its only physical difference from a real emerald is that it does not crack under extreme heat?
The text is amplified by approximately 160 monochrome pictures and 56 pages of full color illustrations of some of the world’s finest jewels.
About the author
Graham Hughes is the author of two standard books, each of which is the only one of its kind: Modern Jewelry and Modern Silver. He has also written many articles in art and academic magazines, and often judges’ competitions.
Studio Vista Publishers
Peerage Books
1972 ISBN 0-907408-30-3
Peerage Books writes:
When a precious stone becomes a jewel, a work of art has been created and a story has begun. In this book, Graham Hughes, Art Director of the Worshipful Company of Goldsmiths of the City of London, tells the story of jewelry—its history, its changing styles, its craftsmen and designers and their techniques, its great collectors and patrons, its discoverers, its value and allure.
He traces the evolution of jewelry style from pre-history to the 1970s, through the great civilizations of Egypt, Greece, Byzantium, Rome and pre-Columbian South America, down through the Dark Ages and medieval times to the Renaissance, the eighteenth century and modern times. Included in this survey are the treasures of Persia, the traveling riches of the barbarians, the abundant gold of Africa and the magnificent, uncountable wealth of India.
Graham Hughes suggests that jewelry may be the oldest art; the most ancient jewels from Ur, Assyria and Babylon, from Pharaonic Egypt, Minoan Crete and Mycenae are evidence that the craft’s basic techniques were already established and well practiced before history began its records. He examines the technique of jewelers: not only modern developments like centrifugal casting machines, but the patience and skill of Etruscan craftsmen who painstakingly affixed by hand tiny, individual granules of gold to create patterns and distinctive finishes. He considers the dominance of that most marvelous metal, gold, which has probably been the chief asset to jewelers everywhere at all times.
From the giant stores of Japan selling jewels by the thousands to the grand and well-known names of jewelry design and business, and the tiny workshops where one or maybe two craftsmen turn their ideas into works of art, Graham Hughes explores the impact of jewelry. He interviews the world’s leading artist-jewelers examining their lives, ideas, attitudes to their creations, and relations with their buying public.
He reminds us of the exiting discoveries of Schliemann, Carter, Sir Arthur Evans and others, who relocated hoards that had been lost for centuries, and takes us on a tour of the great jewelry collections—like the Tsarist treasures, the tears of all Russia—bemoaning the sad fate of jewels which lie in dead museum vaults instead of being worn as their creators intended.
The book ends with an examination of the value and meaning of jewels to different ages of mankind, raising some fascinating questions. Why, for instance, is a Gilson cultured emerald scorned and deemed worthless when its only physical difference from a real emerald is that it does not crack under extreme heat?
The text is amplified by approximately 160 monochrome pictures and 56 pages of full color illustrations of some of the world’s finest jewels.
About the author
Graham Hughes is the author of two standard books, each of which is the only one of its kind: Modern Jewelry and Modern Silver. He has also written many articles in art and academic magazines, and often judges’ competitions.
Tuesday, February 06, 2007
Wall Street Movie
A memorable quote from the movie:
Gordon Gekko (Michael Douglas): The richest one percent of this country owns half our country's wealth, five trillion dollars. One third of that comes from hard work, two thirds comes from inheritance, interest on interest accumulating to widows and idiot sons and what I do, stock and real estate speculation. It's bullshit. You got ninety percent of the American public out there with little or no net worth. I create nothing. I own.
Gordon Gekko (Michael Douglas): The richest one percent of this country owns half our country's wealth, five trillion dollars. One third of that comes from hard work, two thirds comes from inheritance, interest on interest accumulating to widows and idiot sons and what I do, stock and real estate speculation. It's bullshit. You got ninety percent of the American public out there with little or no net worth. I create nothing. I own.
Synthetic Spinel
Gemmology Queensland writes:
Synthetic spinels were first grown by the flame fusion method of synthesis. These early synthetics, which owed their colors to a range of transitional metal chromophores, are easily identified by their high specific gravity of 3.63 and higher refractive index of 1.728. Flux grown synthetic spinels, that primarily originate from Russia are either red or blue in color. As the Russian flux-grown spinels are grown with a 1:1 Al:Mg ratio, their single refractive index (1.71/1.72) and specific gravity (3.60/3.62) are near identical to those of natural spinel color. Fortunately, the presence of solid metalic flux inclusions, and/or reflective grayish platinum will identify flux-grown spinels of Russian origin.
Another synthetic spinel of gemological interest includes a dark blue sintered mass of synthetic spinel powder together with cobalt oxide and specks of gold that has been marketed as a lapis imitation since the early 1950s. This imitation is identifiable by its non-pyrite brassy specks, its brilliant red color when viewed through a Chelsea filter, and its unusually low specific gravity of 3.52.
Synthetic spinel also have been used in the manufacture of an imitation moonstone. This imitation displays a distinct schiller that is thought to be induced into the synthetic spinel by heat treatment. However the distinctive blue-white fluorescence of this imitation when examined under shortwave ultraviolet light readily identifies it.
Synthetic spinels were first grown by the flame fusion method of synthesis. These early synthetics, which owed their colors to a range of transitional metal chromophores, are easily identified by their high specific gravity of 3.63 and higher refractive index of 1.728. Flux grown synthetic spinels, that primarily originate from Russia are either red or blue in color. As the Russian flux-grown spinels are grown with a 1:1 Al:Mg ratio, their single refractive index (1.71/1.72) and specific gravity (3.60/3.62) are near identical to those of natural spinel color. Fortunately, the presence of solid metalic flux inclusions, and/or reflective grayish platinum will identify flux-grown spinels of Russian origin.
Another synthetic spinel of gemological interest includes a dark blue sintered mass of synthetic spinel powder together with cobalt oxide and specks of gold that has been marketed as a lapis imitation since the early 1950s. This imitation is identifiable by its non-pyrite brassy specks, its brilliant red color when viewed through a Chelsea filter, and its unusually low specific gravity of 3.52.
Synthetic spinel also have been used in the manufacture of an imitation moonstone. This imitation displays a distinct schiller that is thought to be induced into the synthetic spinel by heat treatment. However the distinctive blue-white fluorescence of this imitation when examined under shortwave ultraviolet light readily identifies it.
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