Two extraordinary Paraíba-type tourmalines with a remarkable history are headed to the auction block. On September 17, Sotheby’s Hong Kong will offer the Kat Florence “Luminas,” weighing 71.24 and 72.84 carats, respectively — a spectacular set being billed as the largest matched pair of flawless, unheated Paraíba tourmalines ever brought to auction.
Sotheby’s has placed a pre-sale estimate of $382,000 to $510,000 (HK$3 million to HK$4 million) on the pair. The oval gems were cut and fashioned by jewelry designer and artist Kat Florence, who gives the name “Lumina” to exceptional Paraíba-type tourmalines originating from the same remarkable piece of rough.
In 2003, world-famous gem hunter Don Kogen discovered an enormous 830-carat Paraíba tourmaline crystal in the Mavuco district of Mozambique’s Nampula province. Kogen, who is also Florence’s husband and the in-house gem hunter for Kat Florence Atelier, found the crystal during a routine expedition. The intensely saturated neon blue-green stone was notable for its copper-rich composition and extraordinary potential.
Kogen estimated that the huge crystal might one day yield a clean 300-carat gem, an almost mythical prospect in the world of Paraibas, but for more than 20 years the stone lay untouched.
Then in 2025, encouraged by his wife, Kogan agreed to embark on an exacting cutting journey that produced a 315-carat gem. The cut stone was impressive, but not perfect. It displayed “windowing,” an optical effect that can make a gemstone appear flat or see-through instead of allowing its color and brilliance to shine. Rather than accept a compromised result, Florence and her team undertook a painstaking process of analysis and precision recutting.
The effort ultimately produced the 181.61-carat flawless Kat Florence Lumina, which was offered at Bonhams Hong Kong on May 22, 2025, with a pre-sale estimate of HK$3 million to HK$5 million (approximately US$385,000 to $640,000). The remarkable cushion-cut stone ultimately sold for HK$3.814 million, or about US$487,000 including buyer’s premium.
Paraíba tourmalines are among the jewelry world’s most coveted colored gemstones because of their electrifying blue to green hues and exceptional rarity. Their signature color is associated with copper in the crystal’s chemical composition, producing the vivid “neon” appearance that has made fine Paraíba tourmalines legendary among collectors.
The Sotheby’s sale also will feature another extraordinary Kat Florence creation: the largest flawless tanzanite necklace ever to go to auction. Its centerpiece is a spectacular step-cut 424.80-carat tanzanite, fashioned as a royal pendant and surrounded by D-flawless princess- and brilliant-cut diamonds. The necklace carries a pre-sale estimate of HK$2 million to HK$2.8 million (approximately $255,000 to $357,000).
Credits: Photos courtesy of Kat Florence.