Largest known pear-shaped zultanite heads to no-reserve auction from $1

A 36.69-carat pear-shaped zultanite that Zultanite LLC says is the cleanest and largest of its kind will open at US$1 in a live online auction on Oct. 28. The sale puts a rare color-change gem in front of public bidders and could set a fresh market benchmark for large, fine zultanite.

Why it matters: - Zultanite is already scarce, and stones above 30 carats with high clarity are rare enough to draw collector attention. - The auction starts at US$1 with no reserve, so the final price will be set entirely by live bidding. - The sale could establish a public reference point for large zultanite, a gem that usually changes hands privately.

What happened: - Zultanite LLC says a 36.69-carat pear-shaped zultanite will be offered in a live online auction on Gem Rock Auctions on Wednesday, Oct. 28, 2026 at 10:30 p.m. Eastern Time, which is 1:30 p.m. AEDT on Thursday, Oct. 29. - The stone is billed as the largest known pear-shape zultanite and will open at US$1 with no reserve. - The auction will stream live from The Gem Portal’s store on Gem Rock Auctions. - Gem Rock Auctions will publish final prices after the event.

The details: - Zultanite is the trade name for gem-quality color-change diaspore found only in the İlbir Mountains of southwest Turkey and mined by Zultanite LLC. - The stone shows green in daylight and shifts toward brownish-pink and pinkish-red under incandescent light. - Zultanite LLC issued a provenance document describing the stone as the cleanest and largest pear-shape zultanite known to exist, with fewer than a handful of comparable stones known worldwide. - Warasurase Rupasut, head of operations at Zultanite LLC, said flawless zultanite over five carats is already remarkably rare and that a stone above 30 carats with this clarity is of real significance. - Rupasut said the inscription on the girdle matches the certification, giving collectors confidence in what they are bidding on. - Zultanite LLC’s published suggested retail values list zultanite above 20 carats at US$14,000 per carat. - The Gem Portal is offering a 31.27-carat indicolite tourmaline in the same event and on the same terms. - Both stones were examined by Jade and Gems Testing Laboratory in Bangkok. - Report JGTL26T635 identifies the zultanite as natural diaspore weighing 36.69 carats, with no indications of treatment. - Report JGTL26T161 identifies the tourmaline as a natural indicolite tourmaline of 31.27 carats, octagonal cut, vivid blue and internally flawless, with no indications of treatment. - Reports from Bellerophon Gemlab and GIA are pending. - The Gem Portal is a colored gemstone dealer based in Bangkok. - The Gem Portal’s Oct. 14 sale of an 8.3-carat Paraiba tourmaline in the same format drew 72 bids and sold for US$18,625. - Copies of both lab reports are published on the event page. - High-resolution images and lab reports are available on request.

Between the lines: - The no-reserve format is designed to force a true market price discovery, even for stones that are normally traded privately. - The inclusion of lab reports and provenance documents is aimed at reducing uncertainty in a category where treatment, origin and authenticity affect value. - The auction also signals growing willingness to use public live sales for high-end colored stones that would typically stay off-market.

What's next: - Bidders will compete live on Oct. 28, with the top bid determining the sale price. - Gem Rock Auctions will release the final hammer prices after the event. - Additional lab confirmation from Bellerophon Gemlab and GIA is still pending for the lots. - Interested buyers can review the event materials and supporting reports before the sale.