Diaspore as a mineral has been around since its discovery as a species in 1801, but it wasn’t until the 1970′s that this mineral was first faceted for gemstone use. From the 1970′s through 2005 occasional gems were cut from Diaspore for collectors, but in 2006 this mineral started being mined specifically for gemstone use. Though Diaspore is found in several localities throughout the world, the only source of gemstone material is in a Bauxite deposit in the Anatolian Mountains of central Turkey. Originally exploited for its economic importance for the extraction of aluminum, this deposit is now solely mined for the production of this gemstone.

Chemical Formula AlO(OH)
Color Red, Green, Yellow, Pink
Hardness 6.5 – 7
Crystal System Orthorhombic
Refractive Index 1.70 – 1.75
SG 3.3 – 3.5
Transparency Transparent
Double Refraction 0.048
Luster Vitreous
Cleavage 1,2;2,1
Mineral Class Diaspore

Diaspore gemstones are remarkable for their color-changing habit. In daylight or fluorescent lighting, its color is a light yellowish-green to light olive green. In incandescent or candlelight its color changes to light pinkish-orange or raspberry-red color. Diaspore can also show both color combinations in mixed lighting conditions.

Diaspore gemstones can be large and still visibly flawless. Diaspore Cat’s Eyes do occur, but they are rare. Due to the perfect cleavage exhibited on Diaspore, care must be exercised both when cutting and when wearing it as a ring to prevent it from cleaving.

The scientifically recognized mineral name of this gemstone is Diaspore. However, the company that owns the mining rights to the only source of this gemstones had previously promoted this gemstones with the name Zultanite. This is not a scientific or historical name, but rather a marketing brand name introduced by Murat Akgun, the primary owner of the gem deposit. According the previous Zultanite website, the name was in honor of the 36 sultans who ruled the Ottoman Empire. As of August 2012, the name Zultanite was officially dropped by Zultanite Gems LLC, the original promoter of the name Zultanite. The gemstones are now marketed as Gem Diaspore, and the company name has changed from Zultanite Gems LLC to Milenyum Mining LTD.


Diaspore is cut into all different types of cuts for jewelry use, and it is used in rings, earrings, and necklace pendants.


ZultaniteDiaspore gems are not treated or enhanced.The only commercial source of Diaspore gemstones is the Bauxite near Pinarcik, in Mugla, Turkey.The color-changing habits and hardness can distinguish Diaspore from all other gemstones.
Diopside has been regarded only as a collector’s gemstone until recently, when the deep forest-green Chrome Diopside variety has made its way into the mainstream gemstone market. Although its intense green color rivals that of Emerald, its low hardness makes it prone to scratches, thus limiting it from overwhelming the gemstone industry.
Diaspore SOURCES

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