Zultanite’s rarity has three structural causes: (1) single-source origin — gem-quality color-change diaspore comes from one mountain range in Türkiye, with no comparable secondary locality in commercial production; (2) lapidary loss — diaspore’s perfect cleavage on {010} causes ~97% of rough to be lost during cutting, so a kilogram of rough yields ~30 grams of finished gem; (3) trace chemistry — the iron-and-chromium balance that produces strong color change occurs in only a fraction of mined material.

Why this matters

This is one of the cluster support articles for the Zultanite pillar. Each support addresses a single question that buyers, researchers, and writers actually ask, and connects back to the verified properties documented in the property guides.

The verified facts

Mineral species: diaspore (α-AlO(OH)). Locality: İlbir Mountains, Muğla Province, southwestern Türkiye. Hardness: 6.5–7 Mohs. Refractive index: 1.682–1.752. Specific gravity: 3.30–3.39. Color change: sage-green daylight to raspberry-pink candlelight, often through a champagne-gold indoor phase.

Where to read more

See the related property guides on hardness, refractive index, specific gravity, color change, and pleochroism for the verified values behind each claim.