In Facette 30 (March 2026), SSEF's Michael Krzemnicki reports on unheated gem-quality sapphires from Madagascar and Sri Lanka that carry high-field-strength (exotic) elements such as Sn, Nb, Zr, Ta and W. These stones often show velvety blue from fine nano-inclusions in milky clouds.
Raman work found goethite, diaspore and/or strongly metamict zircon, supporting a no-heat call. The same stones can still show FTIR features in the 3309 series, including a 3232 cm⁻¹ peak long treated as a heat marker, plus chalky bluish-white shortwave UV zones that dealers sometimes read as heat. SSEF's point is direct: a single-test shortcut can be wrong on this milky metamorphic material. Trace-element work and inclusion Raman may be needed.
A companion Facette 30 note on an unheated pink Ilakaka sapphire reaches the same practical conclusion: 3232 and 3185 cm⁻¹ peaks can coexist with preserved goethite, which would not survive typical heat temperatures.
For Gem Shop buyers, that is why we disclose heat on every card and lean on reputable reports when a stone is sold as unheated fine goods. It is also why we ask you to watch the turntable video under daylight-balanced light. Milkiness, zoning and windowing show in motion better than in a cropped still. We are not a gem lab. Video is for appearance, not treatment proof.
