Diaspore
Last updated: April 2026
Color-change diaspore marketed as Zultanite or Csarite shifts from kiwi green in daylight to champagne/pink in incandescent light. Commercially sourced almost exclusively from Turkey. Distinct from alexandrite: color shift is green-to-champagne rather than green-to-red. High birefringence (0.048) causes moderate facet doubling visible under 10x loupe.
Physical & Optical Properties
RI Range1.685–1.752
SG Range3.30–3.39
SG Typical3.35
Hardness (Mohs)6.5–7
Crystal SystemOrthorhombic
Optic CharacterDR Biaxial (+)
Birefringence0.048
Dispersion0.020
Fluorescence LWInert
Fluorescence SWInert
Chelsea FilterInert
PleochroismStrong Trichroic
ColorsColor Change, Green, Yellow Orange, Red Pink
SpeciesDiaspore
VarietyColor-Change Diaspore
Key Differentiators
- Color change: green (daylight) → champagne/pink (incandescent) — distinct from alexandrite green-to-red
- High birefringence 0.048 — moderate facet doubling visible at 10x
- Strong trichroism: colorless / pale yellow-green / pink-champagne
- RI 1.685–1.752 (wide spread due to high birefringence)
- Commercially sourced almost exclusively from Turkey
Commonly Confused With
Commonly confused with: Alexandrite.
Treatments
- Heat Treatment (brownish tone reduction)
Price Context
Natural — low ($/ct)$50
Natural — high ($/ct)$500
NotePer carat; fine color-change material from Turkey
Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.
Measurement Guides
Identifying a diaspore? GemID walks through these tests in order — RI, SG, fluorescence, and more.
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