Topic
Mineralogy
Mineralogy entries on Zultpedia document the species-level identity of color-change diaspore: chemistry (α-AlO(OH)), crystal system (orthorhombic), refractive indices, pleochroism, perfect cleavage on {010}, and the trace iron + chromium chromophore mechanism that produces the alexandrite effect. Sourced from primary mineralogical literature (Mindat, Mineralogical Magazine, Wikipedia’s peer-reviewed mineral pages) and the Hatipoğlu et al. 2010 İlbir Mountains study.
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FAQ Cluster
Zultanite — Frequently Asked Questions
Frequently asked questions about Zultanite — gem-quality color-change diaspore from the İlbir Mountains of Türkiye. Twenty Q&A pairs covering identity, rarity, sourcing, color, jewelry use, and buying guidance. Sourced from peer-reviewed mineralogy,…
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Gem Comparison
Zultanite vs Alexandrite — Two Gems, One Phenomenon, Different Propositions
Zultanite (color-change diaspore) and alexandrite (color-change chrysoberyl) are mineralogically unrelated species that produce a similar visual phenomenon — the alexandrite effect — through different chemistries. Alexandrite is harder (8.5 vs 6.5–7 Mohs),…
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Gem Article
The İlbir Mountains — The Single-Source Origin of Color-Change Diaspore
The İlbir Mountains, in Muğla Province on Türkiye's southwestern Aegean coast, are the only place on Earth currently producing gem-quality color-change diaspore. The peer-reviewed locality on record is the Pınarcık area near…
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Gem Article
The Lapidary of Zultanite — Why 97% of the Rough Is Lost in Cutting
Cutting Zultanite costs about 97% of the rough crystal's weight, according to the trademark holder Zultanite Gems LLC. The reason is mineralogical: gem-quality diaspore has perfect cleavage on the {010} plane, so…
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Gem Article
The Color-Change Phenomenon in Zultanite — How and Why It Works
The color-change phenomenon in Zultanite — properly called the alexandrite effect — is a perceptual outcome of selective light absorption, not a property of the stone changing. Trace iron and chromium ions…
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Gem Article
What Is Zultanite? The Color-Change Diaspore from Türkiye
Zultanite is a registered trade name for gem-quality color-change diaspore — α-AlO(OH) — mined exclusively in the İlbir Mountains of southwestern Türkiye. The same material is sold under the parallel trade names…