Posts by Joan

Thanks Lareef for for your detailed reply in response to my post. However, won't the staggering prices achieved recently by some D-color diamonds of Flawless/Internally Flawless clarity greater than 100 carats in weight but with shapes/cut other than round brilliant-cut, give an indication of the ppc-values of D-color RBCs greater than 100 carats in weight ?

The animal and plant motif jewelry lots highlighted by gemlite are indeed exceptional, with unique design features, mostly created by unknown designers. However, three of the lots achieved only a price of less than a thousand US dollars, and one lot slightly above a thousand US dollars (USD1,321). One lot however - Lot 104, Two Antique Ivory and Pearl Pendants and a Gold and Seed Pearl Galleon Brooch - registered a relatively high price of US$7,173. What might have been the cause for the exceptional showing of this antique jewelry lot ?

Out of the six Animal and Plant Motif jewelry lots that appeared at Christie's New York Rockefeller Plaza, Jewels : The New York Sale held on April 22, 2009 and highlighted by Mikegem on August 29, 2014, the lot that realized the highest price of US$86,500 at the auctions was Lot 161 - A Pair of Diamond and Black Diamond Hedgehog Ear Clips designed by JAR. What are the possible reasons for the high price recorded by the JAR jewel ?

The catseye alexandrite and diamond necklace higlighted by Maryjewel is indeed a very rare piece of jewelry. But, what puzzles me most was how it was possible to assemble together 20 large oval-shaped, graduated catseye alexandrites alternating with 20 small round catseye alexandrites to produce the necklace, when finding just one alexandrite in nature is an extreme rarity. Catseye alexandrites are even rarer than normal alexandrites in nature. Hence, the task of putting together such a necklace becomes more complicated. In the absence of a lab report, one might be led to the conclusion that the catseye alexandrites in the necklace are actually lab-grown or synthetic. Unless, the catseye alexandrite rough stones that were subsequently converted to cabochons, were collected over a period of time, from a prolific source of alexandrites such as the Hematita mine in Brazil or the graduated catseye alexandrites were cut from a larger catseye alexandrite rough crystal, the satellite stones still maintaining the chatoyancy.
This explains the ridiculously low ppc value of US$1,785 for these alexandrites.

The images of the two catseye alexandrites highlighted by Mike are indeed very stunning. The purple color of the 5.40-carat catseye alexandrite shows that the image was taken in incandescent light. On the other hand the green color of the 9.01-carat catseye alexandrite reveals that its image was taken in daylight. Both rings are of similar design, with the central catseye alexandrite set within an alexandrite surround of smaller alexandrites of varied cuts. What puzzles me about these images is, that while in the second image taken in daylight both the central catseye alexandrite and the oval-cut stones of the alexandrite surround appear green, as they ideally should be, in the second image taken in incandescent light only the central stone appears purple, while the stones of the alexandrite surround appear green, the typicl color in daylight. What is the cause of this apparent contradiction ?

An exquisitely designed ring by Oscar Heyman & Brothers centered around an 18-carat, cushion-cut, Ceylon pink sapphire, within an octagonal-shaped inner border of calibre-cut square and baguette diamonds, with two large shield-shaped diamonds on either side of this inner border; and an outer border set with smaller pink sapphires cut in a variety of shapes, such as square, rectangular and trapezoids; the shoulders set with baguette-cut diamonds; mounted in platinum, appeared at Sotheby's Geneva Magnificent Jewels Sale held in November 2008. A pre-sale estimate of USD 107,000-149,000 was placed on the ring which sold for an enhanced price of USD 240,690, around USD 90,000 more than the upper estimate. The PPC value of this sapphire works out to USD 13,370 which falls approximately within the range of normal Ceylon pink sapphires.

The unmounted 21.41-carat, cushion-cut alexandrite is certified as of Russian origin, both by the SSEF and LFG. Given this fact, this alexandrite is without any doubt of late 19th or early 20th century origin, the period during which most of the alexandrite deposits of the Ural mountains in Russia was exploited and finally depleted. George Frederick Kunz, gemologist of Tiffany & Co visited the Ural mountains in the late 19th-century, and purchased most of the alexandrites mined during this period on behalf of his company. These alexandrites were incorporated as the centerpiece of many jewelry pieces designed by Tiffany & Co. during this period. Most of these late 19th-century and early 20th-century jewelry pieces incorporating Russian alexandrites are now in family vaults and passed down from generation to generation, and rarely make their appearance at public auctions.
The 21.41-carat, cushion-cut Russian alexandrite is one such rare appearance of a late 19th or early 20th-century alexandrites, mined at the Ural mountains in Russia and perhaps personally handled by George Frederick Kunz himself.