Gemmes & Gemmologie

Lot 72036. Gold Nugget "Lightning Bolt", Victoria, Australia; 10.63 x 2.36 x 1.43 inches (27.00 x 6.00 x 3.64 cm), 1,241 grams (39.9 oz t). Estimate: $70,000 - $100,000.  DALLAS, TX.- An enormous, 40-ounce gold nugget, nicknamed “Lightning Bolt” for its jolting, bright yellow glow and rarity beyond any diamond found on Earth, could take top lot honors in in Heritage Auctions’ Nature & Science Auction Aug. 18. The 11-inch nugget was discovered in Victoria, Australia, and experts have deemed the... [Lire la suite]

Lot 3246Y. Conch Pearl, Strombus gigas or "Queen Conch", Caribbean Sea. Weighing approximately 8.88 carats and measuring 11.84 x 10.26 x 9.52mm. Estimate US$ 10,000 - 12,000 (€ 8,400 - 10,000). © Bonhams 2001-2018 The present offering is of large size: a lovely, non-nacreous pearl that has a classic ovoid shape, as well as an attractive rose color and excellent overall flame pattern iridescence. Bonhams. THE WORLD OF GOLD, OPALS AND OTHER "PHENOMENAL" GEMS, 15 May 2018, 10:00 PDT, LOS... [Lire la suite]

Lot 3245Y. Conch Pearl, Strombus gigas or "Queen Conch", Caribean Sea. Weighing approximately 7.0 carats and measuring 13.02 x 8.73 x 7.94mm. Estimate US$ 7,000 - 9,000 (€ 5,900 - 7,600). © Bonhams 2001-2018 A conch is one of a number of different species of medium-sized to large saltwater snails and their shells. True conchs are marine gastropod mollusks in the family Strombidae, and the most well known species is the Strombus gigas or "Queen Conch". The pearls they produce are calcareous... [Lire la suite]

Lot 3208. Important Color-Change Sapphire, Sri Lanka. Weighing approximately 27.19 carats and measuring 19.0 x 15.6 x 10.19mm. Estimate US$ 120,000 - 150,000 (€ 100,000 - 130,000). © Bonhams 2001-2018 A lovely, unenhanced color-change sapphire with excellent clarity, this "old world" stone exhibits a change of color when viewed under daylight or fluorescent vs. incandescent light. Its large size combined with the prestigious locality and high degree of clarity make this stone an excellent choice for the knowledgeable collector. *... [Lire la suite]

Lot 3169. Rich Black Opal-"The Black Prince II", Lightning Ridge, New South Wales, Australia. Weighing approximately 36.92 carats and measuring 31.5 x 20.2 x 8.4mm. Estimate US$ 65,000 - 85,000 (€ 55,000 - 72,000). © Bonhams 2001-2018 A "nobby" opal, known in the opal trade as "black liquid", this particular example displays a midnight black body color and predominantly vivid, electric green play-of-color with flashes of turquoise, orange and crimson. Having true black potch to the reverse side, the face exhibits what may be termed... [Lire la suite]

Lot 3147. Exceptional Black Pattern Opal-"Fireworks", Lightning Ridge, New South Wales, Australia. Weighing approximately 20.45 carats and measuring 22.5 x 20.4 x 7.9mm. Estimate US$ 120,000 - 140,000 (€ 100,000 - 120,000). © Bonhams 2001-2018 This world-class gem is a memorable pattern opal reminiscent of a starburst or "fireworks". Its focal point is a red lozenge-shaped center from which extend red "rays" and a multitude of rich green, blues, orange hues. The play of color is present and luminous... [Lire la suite]

Lot 3210. Exceptional Chrysoberyl var. Alexandrite, Sri Lanka. Weighing approximately 18.03 carats and measuring 15.87 x 13.54 x 10.19mm. Estimate US$ 200,000 - 250,000 (€ 170,000 - 210,000). © Bonhams 2001-2018 Named for Tsar Alexander II, this rare and beautiful gem, of top quality, is hardly ever used in modern jewelry. In antique Russian jewelry you may come across it with a little luck, since Russian master jewelers loved this stone. Tiffany's master gemologist George Frederick Kunz (1856-1932) was also... [Lire la suite]

Lot 4305. Superb Pair of Red Spinels, Burma. Estimate US$ 50,000 - 60,000 (€ 42,000 - 50,000) © Bonhams 2001-2018 This exceptional pair of red spinels displays a medium-deep tone and vivid saturation of red color, unmasked by brown. They have been faceted as antique cushion cuts which lends them a "old mine" appearance but their optics, faceting, luster and clarity speak for themselves--this is a superlative pair of stones suitable for the knowledgable collector. Weighing 6.14 and 5.70 carats and measuring 10.55 x 9.02 x 7.87mm and... [Lire la suite]

Lot 4306. Very Large Rose Spinel, Tanzania. Estimate US$ 50,000 - 60,000 (€ 42,000 - 50,000) © Bonhams 2001-2018 Distinguished by its exceptional size, this fine spinel displays a deep red rose hue as well as exceptional clarity and luster. It is worthy of consideration by the most serious collector. Weighing approximately 25.77 carats and measuring 18.85 x 15.28 x 11.30 mm. Bonhams. LAPIDARY WORKS OF ART, GEMSTONES, MINERALS AND NATURAL HISTORY, 16 May 2018, 10:00 PDT, LOS ANGELES

Lot 4346. Exceptional Multi-color Tourmaline--"A Member of the 100 Carats Club", Mozambique. Estimate US$ 60,000 - 80,000 (€ 50,000 - 67,000) © Bonhams 2001-2018 This is a world-class tourmaline that would have come from an exceptional crystal. Graduating in color from deep orange at one end to peach in the center and bottle green at the other end. The clarity is eye clean and exceptional as is the luster. Weighing approximatley 112.71 carats and measuring 35.80 x 19.41 x 16.87mm. Bonhams. LAPIDARY WORKS OF ART, GEMSTONES,... [Lire la suite]