Bonhams & Butterfields is to hold a sale named The Nature of Opals in six weeks' time in San Francisco. The sale will be among the first auctions in the US devoted to Opals and the first dedicated offering in this category for the auctioneer.
Featured highlights will include a diverse group of high quality and distinctive jewellery, unmounted stones, mineral specimens, lapidary works of art, decorative objects, décor and opalised fossils, made from the opulent gem.
All of nature's grandeur appears to be reflected within the diverse richness of Opals. Elements such as fire, water, air and sea are mirrored within each opulent gem.
Opal has a non-crystalline nature and is composed of microscopic silica spheres in a hexagonal lattice matrix. The complex order of these spheres gives the gem its multifaceted colouring and unique personality.
Opals range in hue from clear, such as Mexican Fire Opals on offer during the November auction, through to red, orange, yellow, green, blue, pink, brown, and black.
Commonly referred to as "opalising," the continually changing play of colours, boasts radiant intensity within each colour variation. Examples from the Virgin Valley, Nevada; the United States; Mexico; Brazil; Peru; Europe; Ethiopia and Australia, where the item is considered is the national gemstone, will be offered in the sale
One of the top lots of the sale is a stunning Opal and 18K Gold Presentation Box by famed lapidary artist, Manfred Wild of Idar-Oberstein, Germany (est. $100,000 - 150,000). Set with a large 224.24-carat oval cabochon of white opal from Coober Pedy, Australia, the piece also contains black matrix opal that has been used to create the inset panels.
The jewellery section features the work of several notable designers and includes a flaming tangerine-red; Mexican Fire Opal and diamond necklace, mounted in 18K yellow gold, comprised of 40 Opal cabochons and 11.3-carats of diamonds (estimated at $20,000-30,000) with a matching pair of earrings ($2,500-3,500).
Other highlights include a black opal and cultured pearl necklace by renowned Boston jewellery designer, Angela Conty (listed at $10,000-15,000), a figure of a bear constructed of highly sought after white Australian Opals in a diamond-set brooch mount (estimated at $13,000-15,000) and an Andamooka Opal carving of Buddha (est. 2,500-3,500).
A brilliant pendant constructed of 12.25-carats of Opals surrounded by 40 diamonds ($5,500-6,500) and a subtly coloured Opal flower brooch ($2,800-3,250), will also be on offer.
Opalised wood is also represented within the sale by a unique example of a large tree limb in which the cellular structure of the tree has been replaced by opalisation. Weighing in at a hefty 45kg , the extraordinary specimen from Koroit, Queensland, Australia, measures approximately five feet long and is expected to bring $35,000-45,000.
Opalised fossils known to originate in Coober Pedy, Australia will also be featured in the November sale. Highlights will include a rare opalised jawbone section of the Cretaceous sea creature Pleiosaur, contour polished on one face to reveal the brilliant spectral play-of-colour within (est. $24,000-28,000).
"The Opal is highly sought after by connoisseurs, gemstone and jewellery collectors for its unique optical properties. The market for the gem remains strong and the exceptional examples, such as those featured in the November auction, are extremely rare," said Claudia Florian, Co-Consulting Director of Bonhams' Natural History department, who is curating the auction.
Bonhams & Butterfields is a global leader in the Natural History marketplace, able to present a variety of jewellery, gemstones, fossils and minerals at impressive prices. As recently as June 2008, the firm sold perhaps the most famous and recognizable opal in the world - the Flame Queen - for $120,000.
Extraordinary not only for its large size (263.18-carats), but also for its unusual shape and colour pattern, the Flame Queen was one of only a handful of large museum-quality opals known, even fewer have ever been offered at public auction.
Exhibitions will continue throughout the fall in celebration of the Opal as the birthstone for the month of October. Highlight previews will be held in Los Angeles from October 1-3 and New York from October 16-18 before a full preview for three days in San Francisco in the run-up to the auction on November 10.