Gemstone Market Update | September 9, 2026

A Giant Paraíba Tests the Value of Origin

Sotheby's September 17 High Jewelry auction in Hong Kong will test one of the colored-stone market's most striking distinctions: size alone does not determine rarity. A 7.52-carat unheated Brazilian Paraíba tourmaline ring carries an estimate of HK$7.8 million to HK$15.5 million. In the same sale, a far larger pair of unmounted Mozambique Paraíba-type tourmalines, 71.24 and 72.84 carats, has an estimate of HK$3 million to HK$4 million. The lots cannot be compared solely by price per carat because their color, clarity, cutting, mounting and documentation differ. They do, however, illustrate the premium the trade may place on geographic origin. Sotheby's notes that Brazilian Paraíbas are commonly under one carat and that the original deposits neared exhaustion around 1992. These figures are presale estimates, not completed-sale prices. Read Sotheby's account of Paraíba tourmaline.

When a Genuine Report Becomes Outdated

The Swiss Gemmological Institute SSEF has warned of recent cases in which emeralds were cleaned before laboratory testing, received reports recording no or only minor clarity modification, and were subsequently refilled with oil or artificial resin. The emeralds were then offered with the earlier reports. The documents were genuine, but the stones no longer matched the condition recorded when they were examined. SSEF recommends verifying reports and obtaining fresh testing when an emerald is highly fissured, its report is not recent or the stone appears unusually clean. For buyers and dealers, both the authenticity of the report and the gemstone's present condition matter. Read the SSEF trade alert.

What GIA Is Seeing

GIA's latest Tucson report documented hydrothermal laboratory-grown emeralds produced to imitate the color and appearance associated with Colombian material, including one weighing 66.57 carats. In a separate Gems & Gemology report, a red spinel represented as Tanzanian showed evidence of heating through photoluminescence testing and microscopic examination. GIA reports that most spinel arriving at gemological laboratories is untreated; oiling is encountered most frequently, while heating remains rare. The practical lesson is that “Colombian-looking” is not an origin determination, and an uncommon treatment cannot be assumed absent simply because it is unusual. Read GIA's Tucson report. Review the spinel lab note.

Trade Term: Clarity Modification

“Clarity modification” describes the treatment of surface-reaching fissures, commonly with colorless oil, wax or resin, to make them less visible. It does not make an emerald synthetic, but the filler and its extent can affect value, disclosure and care. A report's treatment finding describes the condition observed when the laboratory examined the stone.

Top Five Demand Watch

There is no centralized, real-time index ranking worldwide colored-gemstone demand. This week's list is Pryce House's editorial ordering of the strongest demand signals reported in GIA's 2026 Tucson market review, not a universal price ranking.

1. Fancy-color sapphire: Exhibitors carrying numerous gem varieties identified these as the shows' most popular stones, particularly pink, purple, teal and green sapphires. Montana sapphires over one carat also drew strong American and international demand.
2. Star ruby and star sapphire: GIA described corundum displaying asterism as some of the hottest material at the 2026 shows.
3. Garnet: Tucson vendors reported strong garnet sales across multiple varieties and price levels.
4. Rainbow moonstone: Material from Madagascar continued to sell quickly among buyers.
5. Guatemalan blue jadeite: GIA identified this as a newer popular material, with its teal color matching one of the year's prominent market colors.

Natural gemstones are defined by more than species and color. Origin, treatment history, laboratory documentation, cutting and prior ownership all shape how a stone is understood in the trade. Pryce House sources distinctive natural colored stones through estates, private collections and established secondary-market channels, returning origin-specific material to buyers who value what cannot simply be manufactured again. For private access, enter The Stone Room.

Auction estimates concern specific lots and are not sale results, appraisals or general price benchmarks. Colored gemstones do not trade through one universal index. This update is provided for general information and is not investment, appraisal, tax or legal advice.