Demantoid garnet is the rarest of all garnets and is one of the most precious of all gemstones. Yet, few people have heard of it.
The word demantoid means diamond-like in Dutch.
Garnet comes in a variety of colors – pink, purple, violet, orange, yellow, colorless, brown, black, several shades of green, and yes, many shades of red.
But the demantoid garnet is the rarest and most valuable.
First found in the Ural Mountains of Russia in 1868, this gem was favored by the Russian Imperial Court jeweler Peter Carl FabergE for its unrivaled brilliance and intense coloration.
Demantoids were used in many of the jewelry and objects Fabergé created, including the Imperial Easter Eggs, commissioned by Alexander III and Nicholas II as Easter gifts to their Tsarinas.
Demantoid garnet is one of the few colored gemstone to display dispersion – the rainbow colors given off when light is refracted as it hits the facets of a gem – like a prism. Diamonds are well known for its high dispersion but demantoids have an even higher dispersion rate than diamonds!
Today, demantoids are found in several places around the world including Italy, Aghanistan and Iran but the major deposits are in Madagascar, Namibia and Russia.
One very distinctive inclusion in demantoid garnets are what’s called ‘horsetail’ inclusions. These are long, fine chrysotile needles radiating out from the center which appear to resemble a horse’s tail. Instead of decreasing the value, a well-formed horsetail can actually increase the value. However, only demantoids from Russia will have this type of inclusion.
Demantoids are hardly ever found larger than 2.0 carats after cutting. This makes larger specimens exceedingly rare.