Demantoid

Demantoid, meaning diamond-like, after the Dutch word "demant" for diamond, possess an unusual green color and a dispersion even greater than diamond.

From a historical perspective, Demantoid is clearly the most important variety of the Andradite species. Demantoids from the Ural mountains of Russia were discovered in 1868. Possessing an unusual green color and a dispersion even greater than diamond, demantoid quickly became a treasured and expensive gemstone and was used by the famous Russian jeweler Faberge to create jewelry.

The distinctive features of Russian demantoids are the characteristic inclusions of yellow byssolite (asbestos) fibers with radiating arrangements known as horsetails. Although the horsetails are diagnostic for demantoid, they are not required for a stone to be identified as a demantoid. The identification of demantoid is based on the chemistry and refractive index of the stone and many stones do not have horsetails at all.

More recently, demantoids have also been discovered in Madagascar, Namibia, Iran, and Pakistan but these stones are not known to show any horsetails. Russian demantoids are by far the most expensive and valuable and their valuations are typically 4- 5 times more than demantoids from any other sources.

Overview

Related

See also

Loose gemstones