28 juillet 2008

Impressive Opal “Pineapple” Pseudomorph after Glauberite. White Cliffs, New South Wales, Australia

Impressive Opal “Pineapple” Pseudomorph after Glauberite. White Cliffs, New South Wales, Australia A rare example of an opal pseudomorph after glauberite is this specimen known in the mineral hobby as a “pineapple”. The White Cliffs region of New South Wales, Australia is the only known locality for these specimens. Pseudomorphs are mineral specimens where one mineral has taken the form of a previously deposited mineral. While the process may sound simple, it is actually quite complicated. Some pseudomorphs are created when a... [Lire la suite]
Posté par Alain Truong à 22:00 - - Commentaires [0] - Permalien [#]
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28 juillet 2008

Opale. Opal Butte, Oregon

Opale. Opal Butte, OregonOpal Butte is the other major American locality for gem opal suitable for use in carving and jewelry. Rarely does one find large enough chunks of nearly pure opal that are attractive enough throughout to serve as specimens, or decorative display pieces. The present specimen is transparent to translucent and has wonderful sunset shades of yellows, reds, and oranges. Much of the 447 grams weight is of carving quality.  Weighing 447 grams and measuring 4 x 4 x 2 ½in - Estimate: $5,000 - 6,000 -... [Lire la suite]
Posté par Alain Truong à 21:55 - - Commentaires [0] - Permalien [#]
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13 juillet 2008

Very Large Melo Pearl - Saltwaters near Vietnam

Very Large Melo Pearl - Saltwaters near Vietnam Relatively unknown in the West, even George Kunz’s compendium of 1908, The Book of the Pearl, had no references to the rare orange pearl offered here. So few have been found, it is no wonder. The Melo melo is the marine snail that produces orange pearls the color of a ripe papaya. The snail generates a pearl-like substance to enclose foreign bodies, or irritants, entering its shell. Both orange and pink pearls (from the Conch, Strombus gigas) are “non-nacreous”, meaning they... [Lire la suite]
Posté par Alain Truong à 17:17 - - Commentaires [0] - Permalien [#]
13 juillet 2008

Purple Spinel. Vietnam

Purple Spinel. Vietnam A pretty oval-cut gem with brilliant luster, and fine transparency and a slightly lavenderish-purple hue. Weighing approximately 7.01 carats and measuring 12.0 x 10.5 x 6.2mm. Estimate: $2,000 - 2,500 - Unsold (Copyright © 2002-2008 Bonhams 1793 Ltd., Images and Text All Rights Reserved) Bonhams. Natural History, 22 Jun 2008. 220 San Bruno Street, San Francisco // 7601 Sunset Blvd., Los Angeles - www.bonhams.com
Posté par Alain Truong à 16:53 - - Commentaires [0] - Permalien [#]
13 juillet 2008

Ruby Spinel (Vietnam)

Ruby Spinel. Vietnam A pretty, cushion-shaped stone of rich red color and very good clarity suitable for mounting as a ring stone. Weighing approximately 2.59 carats and measuring 9.0 x 6.5 x 5.0mm - Estimate: $1,500 - 2,000 - Unsold (Copyright © 2002-2008 Bonhams 1793 Ltd., Images and Text All Rights Reserved) Bonhams. Natural History, 22 Jun 2008. 220 San Bruno Street, San Francisco // 7601 Sunset Blvd., Los Angeles - www.bonhams.com
Posté par Alain Truong à 16:45 - - Commentaires [0] - Permalien [#]
30 mai 2008

AN UNMOUNTED BRILLIANT-CUT DIAMOND Weighing 12.15 carats

AN UNMOUNTED BRILLIANT-CUT DIAMOND Weighing 12.15 carats Price Realized: HK$18,807,500 ($2,420,901) With report no. 8340199 dated 13 August 2007 from the Gemological Institute of America stating that the 12.15 carat diamond is D colour, flawless clarity, with excellent cut, excellent polish and excellent symmetry WHITE MAGICWhite diamonds offer a breathtaking landscape across areas of cut, colour, clarity and carat weight where the magic of these extraordinary stones rests upon a wonderful interplay of these features.... [Lire la suite]
Posté par Alain Truong à 23:24 - - Commentaires [0] - Permalien [#]

27 mai 2008

An unmounted cat's eye chrysoberyl weighing 35.93 carats

An unmounted cat's eye chrysoberyl weighing 35.93 carats The cat's eye chrysoberyl weighing 35.93 carats. Estimate: HK$2,200,000 - 3,200,000, $280,000 - 410,000 Footnote: Accompanied by a gemological report from Gemresearch Swisslab, stating that the cat's eye chrysoberyl is natural and is of vivid greenish-yellow colour. The report also states that the cat's eye chrysoberyl is of Sri Lanka origin and displays a sharp cat's eye effect. Report number GRS2007-011425, dated 22nd January 2007. (Copyright © 2002-2008... [Lire la suite]
Posté par Alain Truong à 20:36 - - Commentaires [0] - Permalien [#]
02 mai 2008

A HIGHLY IMPORTANT ORANGE NATURAL PEARL

A HIGHLY IMPORTANT ORANGE NATURAL PEARL The yellow to iridescent pinkish orange pearl measuring 21.1 by 19.4 mm and weighing 241.44 grains (60.36 carats), the pearl has not been drilledAccompanied by report No. 0127771 dated 07 December 2007 from the Gemmological Association of Great Britain (Gem-A) stating that the pearl is naturalAn appendix from Gem-A to the above report states that 'the combination of fine lustre even shape and size in this pearl are noteworthy, but its colour described as 'yellow to pinkish orange' is... [Lire la suite]
Posté par Alain Truong à 22:24 - - Commentaires [0] - Permalien [#]
01 mai 2008

Cinnabar, China

Cinnabar, ChinaWhile Greek texts mention the use of cinnabar—the naturally occurring form of vermilion—in as early as sixth century B.C., early Chinese artifacts show traces as far back as the second millennium B.C, and its use in pigments continues to this day. The name is derived from the Persian zinjifrah and the Latin word cinnabaris although the original meanings of both have been lost. Cinnabar, a heavy red from of mercuric sulfide, occurs as brilliant red crystals in mountainous regions of volcanic origin usually close to... [Lire la suite]
Posté par Alain Truong à 19:33 - - Commentaires [0] - Permalien [#]
01 mai 2008

Extremely Large Rutilated Quartz Cabochon - Brazil

Extremely Large Rutilated Quartz Cabochon - Brazil An exceedling large desktop or cabinet specimen, this oval cabochon of rather transparent rock crystal quartz contains needle-like inclusions of rutile. Rutile is the natural mineral form of titanium dioxide. It is generally dark red or metallic black its name rutile coming from the Latin for “dark red”. It forms prismatic crystals that can be thin as hairs, as in this specimen of rutilated quartz. Rutile forms twins and sprays of six or eight crystals frequently... [Lire la suite]
Posté par Alain Truong à 19:00 - - Commentaires [0] - Permalien [#]