Name: Demantoid Garnet
Moh Hardness Scale: 7.5
Specific Gravity: 3.84
Refractive Index: 1.9
The garnets are a family of gemstones, and to the uninformed are regarded as a collective of less precious stones. However, there exist within this group certain types which command a high price, and none is more valued than the demantoid garnet.
Demantoid garnets are some of the most brilliant of all gemstones. Their refractive index is higher than the corundums and they are only outdone by diamonds and zircons in this regard. They are one of the few gemstones that are singly refractive. Hence the designation demantoid (diamond-like), as this is a property shared with the more famous gemstone.
The demantoid garnet outdoes even diamonds as regards light dispersion (or fire) and at times its lustre comes close to sphalerite’s.
Relatively unknown until recently, demantoid gems are becoming a force in the gemstone market. Currently only two sources of these gems exist, an original source in Russia and a more recent one in Namibia. Of the two, Russian demantoids are particularily prized and can be recognized by a distinctive horsetail inclusion.
You can find demantoid garnets on bidorbuy.