Color-change diaspore — the mineral species — was first described by René Just Haüy in 1801 in the Mineralogie volume of his foundational works. Gem-quality material from the İlbir Mountains of southwestern Türkiye, which combines diaspore’s mineralogy with the trace-element profile required for the alexandrite effect, was not commercially developed until the late 20th century, with structured production beginning in the early 2000s.

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.