Diaspore
A variety of Diaspore Group
What is Diaspore?
The most valuable and highly-sought type of diaspore is Zultanite, a rare, transparent, faceted gem which is mined and manufactured in Turkey. This type is significantly larger than other forms of diaspore, which are considered valueless in the gemstone trade. This mineral is a component of Bauxite, which is regularly used as a source of aluminum.
Etymology & Origins
It was first described in 1801 for an occurrence in Mramorsk Zavod, Sverdlovskaya Oblast, Middle Urals, Russia. The name, which was coined by René Just Haüy, is from the Greek for διασπείρειν, to scatter, in allusion to its decrepitation on heating.
Uses & Applications
Diaspore is valued for its refractory properties and is used most frequently to make refractory bricks; low-quality pieces are a filler for the plastics industry. Gem-quality pieces from Turkey are sold under the trade names csarite, ottomanite, and zultanite.
Optical Properties
- Refractive Index
- 1.702-1.750
- Birefringence
- 0.048
- Optical Character
- Biaxial positive
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Diaspore before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Diaspore Localities Map
See where Diaspore is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
The Meaning
Diaspore is a birthstone for the zodiac sign of Pisces.
Quick Facts
Physical Properties
- Color
- white, brown, colourless, pale yellow, greyish, greenish grey, lilac, pinkish
- Hardness (Mohs)
- 6.5 - 7
- Density
- 3.38 g/cm³
- Streak
- white
- Luster
- Pearly, Vitreous
- Crystal System
- Orthorhombic
Chemical Properties
- Chemical Formula
- AlO(OH)
- Elements
- Al, H, O
Also Known As
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Diaspore FAQs
How do I identify Diaspore?
Diaspore can be identified by its hardness of 6.5 - 7 on the Mohs scale, white color, Pearly, Vitreous luster, Orthorhombic crystal system. Look for these key characteristics when examining specimens.
What color is Diaspore?
Diaspore typically appears in white, brown, colourless, pale yellow, greyish, greenish grey, lilac, pinkish. Color can vary depending on impurities and formation conditions.
How hard is Diaspore?
Diaspore has a hardness of 6.5 - 7 on the Mohs scale. This gives it moderate hardness.
