Wednesday, October 03, 2007
The Top 50
The Guardian profiles UK's brightest/biggest designers + their concepts @ http://arts.guardian.co.uk/art/design/story/0,,2159165,00.html
The Istanbul Biennial
Peter Schjeldahl writes about The Istanbul Biennial, one of the first non-Western biennials, and one of only a few in Muslim countries + its fun-filled, earnest concepts + other viewpoints @ http://www.newyorker.com/arts/critics/artworld/2007/10/08/071008craw_artworld_schjeldahl
About The Turner Prize
(via The Guardian) Jonathan Jones writes about the Turner prize + other viewpoints @ http://arts.guardian.co.uk/art/news/story/0,,2181514,00.html
Useful links:
Turner prize 2007
In pictures: the shortlisted artists
About Mark Wallinger
Adrian Searle on Mark Wallinger's State Britain
What do you think of State Britain?
State Britain in pictures
Adrian Searle on Wallinger's Trafalgar Square sculpture
Mark Wallinger's 1995 Turner prize entry
About Zarina Bhimji
Adrian Searle reviews Documenta
Yasmin Alibhai-Brown on Muslim artists in Britain
Zarina Bhimji official site
Haunchofvenison.com: biography of Bhimji
About Nathan Coley
Adrian Searle on 2005's macabre summer shows
Doggerfisher.com: see works by Nathan Coley
About Mike Nelson
News: Art on drugs in Margate
Jonathan Jones talks to Mike Nelson
Mike Nelson's 2001 Turner prize entry
Tate: Mike Nelson profile
Mike Nelson at Frieze Art Fair
Special report
Full coverage: Turner prize 2006
Useful links:
Turner prize 2007
In pictures: the shortlisted artists
About Mark Wallinger
Adrian Searle on Mark Wallinger's State Britain
What do you think of State Britain?
State Britain in pictures
Adrian Searle on Wallinger's Trafalgar Square sculpture
Mark Wallinger's 1995 Turner prize entry
About Zarina Bhimji
Adrian Searle reviews Documenta
Yasmin Alibhai-Brown on Muslim artists in Britain
Zarina Bhimji official site
Haunchofvenison.com: biography of Bhimji
About Nathan Coley
Adrian Searle on 2005's macabre summer shows
Doggerfisher.com: see works by Nathan Coley
About Mike Nelson
News: Art on drugs in Margate
Jonathan Jones talks to Mike Nelson
Mike Nelson's 2001 Turner prize entry
Tate: Mike Nelson profile
Mike Nelson at Frieze Art Fair
Special report
Full coverage: Turner prize 2006
Orthodox Bulldozer
Konstantin Akinsha writes about the background of rising nationalism and Orthodox assertiveness by Russian Orthodox activists + the influential members of the congregation of St. Nicholas in Pyzhi (whose archpriest, Alexander Shargunov, is a well-known radical fundamentalist) + the Sakharov Museum controversy + other viewpoints @ http://artnews.com/issues/article.asp?art_id=1521
Selling Diamonds
(via Diamond Promotion Service) 21. The diamonds are separated from the concentrate in the final steps of recovery. Until recently, this was done primarily by grease tables or grease belts. Diamonds are water-resistant; therefore when the concentrate is sluiced over tables or moving belts coated with a heavy grease, the diamonds stick to the grease and the rest of the material is washed away. Then the diamonds and grease are scraped up and put into boiling water which cleans away the grease.
22. The latest development for this final recovery is X-ray separation. A diamond fluoresces in an X-ray beam. The diamondiferous concentrate passes a beam. The fluorescence triggers a photoelectric cell, which in turn, trips a jet of air that blows the diamond out of the main stream. When another mineral passes the electronic eye, nothing happens. This method of separation is incredibly fast, and it’s more than 99 percent effective.
23. In alluvial mines, the diamonds are usually found among the gravels and other material lying on the bedrock. The sand or earthen overburden is scraped up and dumped in an other location. Then the diamond-bearing gravels are scooped up and taken away for the recovery treatment. Every crevice of the bedrock is swept clean with brooms to make sure that they get all the diamonds. The recovery process is essentially the same as for ore from the open cast and underground mines.
24. The ratio of diamonds within the diamond-bearing rock is very low. In some mines, to recover one ounce of diamonds—which is 142 carats—the miners have to dig as much as 112,000,000 ounces of material—which is 3500 tons. Furthermore, the average size of the rough diamonds is less than a carat. So in one ounce of rough—142 carats—there may be only half a dozen stones larger than a carat, and a couple of hundred smaller than half a carat.
25. Of the total world production of rough diamonds, only about 20 percent are capable of being cut into gem diamonds. The rest are put to industrial use for the cutting, grinding and polishing of a great variety of materials used in manufacturing. The gem-industrial ratio varies from country to country. Production in the Republic of Zaire (DR Congo) runs more than 98 percent industrial while that of South-West Africa is more than 90 percent gem.
26. Broadly, diamonds are sorted in the following categories: stones, which are octahedral in shape and look like two four-sided pyramids joined at their bases; cleavages, or broken and blocky pieces; macles, which are triangular stones usually with a herring-bone line around them; and flats, or thin but cuttable diamonds. Stones and shapes weighing less than one carat in the rough are known as melee. Cleavages under one carat in the rough are known as chips. Bort, ballas and carbonado are varieties of diamond used only in industry.
27. Synthetic diamonds for industrial uses are being manufactured by subjecting graphite compounds to tremendous heat and pressure in giant presses. Synthetic gem diamonds have been made in laboratory experiments, but only at great cost, far more than the cost of natural gem diamonds.
Selling Diamonds (continued)
22. The latest development for this final recovery is X-ray separation. A diamond fluoresces in an X-ray beam. The diamondiferous concentrate passes a beam. The fluorescence triggers a photoelectric cell, which in turn, trips a jet of air that blows the diamond out of the main stream. When another mineral passes the electronic eye, nothing happens. This method of separation is incredibly fast, and it’s more than 99 percent effective.
23. In alluvial mines, the diamonds are usually found among the gravels and other material lying on the bedrock. The sand or earthen overburden is scraped up and dumped in an other location. Then the diamond-bearing gravels are scooped up and taken away for the recovery treatment. Every crevice of the bedrock is swept clean with brooms to make sure that they get all the diamonds. The recovery process is essentially the same as for ore from the open cast and underground mines.
24. The ratio of diamonds within the diamond-bearing rock is very low. In some mines, to recover one ounce of diamonds—which is 142 carats—the miners have to dig as much as 112,000,000 ounces of material—which is 3500 tons. Furthermore, the average size of the rough diamonds is less than a carat. So in one ounce of rough—142 carats—there may be only half a dozen stones larger than a carat, and a couple of hundred smaller than half a carat.
25. Of the total world production of rough diamonds, only about 20 percent are capable of being cut into gem diamonds. The rest are put to industrial use for the cutting, grinding and polishing of a great variety of materials used in manufacturing. The gem-industrial ratio varies from country to country. Production in the Republic of Zaire (DR Congo) runs more than 98 percent industrial while that of South-West Africa is more than 90 percent gem.
26. Broadly, diamonds are sorted in the following categories: stones, which are octahedral in shape and look like two four-sided pyramids joined at their bases; cleavages, or broken and blocky pieces; macles, which are triangular stones usually with a herring-bone line around them; and flats, or thin but cuttable diamonds. Stones and shapes weighing less than one carat in the rough are known as melee. Cleavages under one carat in the rough are known as chips. Bort, ballas and carbonado are varieties of diamond used only in industry.
27. Synthetic diamonds for industrial uses are being manufactured by subjecting graphite compounds to tremendous heat and pressure in giant presses. Synthetic gem diamonds have been made in laboratory experiments, but only at great cost, far more than the cost of natural gem diamonds.
Selling Diamonds (continued)
Tuesday, October 02, 2007
How Green Was My Valley
Greatest Opening Film Lines (How Green Was My Valley - 1941):
I am packing my belongings in the shawl my mother used to wear when she went to the market. And I'm going from my valley. And this time, I shall never return. I am leaving behind me my fifty years of memory. Memory. Streams that the mind will forget so much of what only this moment has passed, and yet hold clear and bright the memory of what happened years ago - of men and women long since dead.
I liked this one.
I am packing my belongings in the shawl my mother used to wear when she went to the market. And I'm going from my valley. And this time, I shall never return. I am leaving behind me my fifty years of memory. Memory. Streams that the mind will forget so much of what only this moment has passed, and yet hold clear and bright the memory of what happened years ago - of men and women long since dead.
I liked this one.
Common Gemstone Treatments
A number of gem materials are treated to alter their appearance. Temperatures may vary considerably depending on the material and the desired effect. In some cases relatively low temperatures may cause the desired change (s).
Amber may be heated to produce a number of desired changes. Most commonly it is heated to induce discoid fractures known as ‘sun spangles’ that some consider desirable. It may also be heated to change yellow material to a darker, more orange brown color, thereby resembling naturally age-oxidized material. Cloudy amber containing a myriad of tiny gas bubbles may be clarified by heating, usually while immersed in an oil medium (rapeseed or linseed oil). The presence of sun spangles is generally assumed to imply treatment whereas the heat oxidation and clarification processes are not normally detectable.
Aquamarine, a beryl variety, most commonly occurs in nature as a blue-green stone, the color from which it derives its name (meaning seawater). Today, however, a purer blue is more marketable. Heat treatment is therefore used to remove the yellow component of its color, leaving the stable blue. The same treatment is used to remove the yellow component from some peachy morganite beryl, resulting in a purer pink color. Because of the relatively low temperatures used, heat treated aquamarine and morganite rarely show the type of heat-treated damage used to determine heat treatment in some corundum, so detection is generally not possible.
One of the commercially more significant varieties of quartz is amethyst. The stone is heated to improve the color of dark-toned material by bleaching out some of the purple color and/or removing a smoky component. In both cases the heating (partially or completely) reverses radiation-induced structural damage that produced color centers. Heating to high temperatures is routinely used on amethyst from some sources to produce the yellow quartz variety, citrine. It is believed that practically all of the citrine on the market today is the result of such treatments. Some amethyst, upon heating, will convert to citrine in some zones and not others; this results in the bi-colored amethyst-citrine variety that has marketed under the trade name Ametrine.
Some brown to orange topaz owes its color to a combination of a chromium-produced pink component and color-center-produced yellow-to-brown component. Heating such materials repairs the structural damage that produces the yellowish component, leaving only the stable pink color. This process, which requires relatively low temperatures, is referred to as ‘pinking’. The material reportedly shows stronger dichroism than untreated natural pink topaz. Heating is also a step in the production of some irradiated blue topaz, as some irradiation sources will produce color centers for both blue and yellow to brown colors. The heating removes the yellowish component, leaving the more stable blue color.
Amber may be heated to produce a number of desired changes. Most commonly it is heated to induce discoid fractures known as ‘sun spangles’ that some consider desirable. It may also be heated to change yellow material to a darker, more orange brown color, thereby resembling naturally age-oxidized material. Cloudy amber containing a myriad of tiny gas bubbles may be clarified by heating, usually while immersed in an oil medium (rapeseed or linseed oil). The presence of sun spangles is generally assumed to imply treatment whereas the heat oxidation and clarification processes are not normally detectable.
Aquamarine, a beryl variety, most commonly occurs in nature as a blue-green stone, the color from which it derives its name (meaning seawater). Today, however, a purer blue is more marketable. Heat treatment is therefore used to remove the yellow component of its color, leaving the stable blue. The same treatment is used to remove the yellow component from some peachy morganite beryl, resulting in a purer pink color. Because of the relatively low temperatures used, heat treated aquamarine and morganite rarely show the type of heat-treated damage used to determine heat treatment in some corundum, so detection is generally not possible.
One of the commercially more significant varieties of quartz is amethyst. The stone is heated to improve the color of dark-toned material by bleaching out some of the purple color and/or removing a smoky component. In both cases the heating (partially or completely) reverses radiation-induced structural damage that produced color centers. Heating to high temperatures is routinely used on amethyst from some sources to produce the yellow quartz variety, citrine. It is believed that practically all of the citrine on the market today is the result of such treatments. Some amethyst, upon heating, will convert to citrine in some zones and not others; this results in the bi-colored amethyst-citrine variety that has marketed under the trade name Ametrine.
Some brown to orange topaz owes its color to a combination of a chromium-produced pink component and color-center-produced yellow-to-brown component. Heating such materials repairs the structural damage that produces the yellowish component, leaving only the stable pink color. This process, which requires relatively low temperatures, is referred to as ‘pinking’. The material reportedly shows stronger dichroism than untreated natural pink topaz. Heating is also a step in the production of some irradiated blue topaz, as some irradiation sources will produce color centers for both blue and yellow to brown colors. The heating removes the yellowish component, leaving the more stable blue color.
Designers' London
(via The Observer) It's all about top designers and their inspirations + the places and spaces in London that motivates them most + other viewpoints @ http://arts.guardian.co.uk/art/design/story/0,,2162272,00.html
Subscribe to:
Comments (Atom)