Demantoid Garnets and their "Fireworks" or "Horsetail" Inclusions

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In 1868, demantoid garnets were first discovered in Russia, near the village of Elizavetinskoye and the Bobroka river. Being the green variety of the andradite garnet species, demantoid today functions as a popular collector's gem, being prized for its high dispersion rate, which allows it to showcase spectral colors when rocked and tilted. The stone possesses a high refractive index and luster that is significantly sharper than most other colored gemstones.

Demantoid is one of two green garnet varieties that are frequently seen in the modern jewelry trade, the other being tsavorite; the green variety of grossularite garnet. Unlike tsavorite, demantoid can have diagnostic inclusions that notably increase their values due to popular demand. "Horsetail" or "Fireworks" inclusions are radiating thin needles of chrysotile that are frequently seen in certain demantoid specimens.

This variety of garnet gains its green color from the presence of a trace element called chromium. Additionally, the presence of iron also causes a yellowish modifying color in most stones, however pure green colors are more highly sought after, and correspondingly more valuable. Demantoid actually got its name from the french word 'demant' which refers to diamond. This is because it shares many similar properties with the world's most famous colorless gem. Demantoids have strong spectral fire, and incredibly high luster, which caused a lot of people to compare it with diamond during the years after its initial discovery.

(Photography credit: Sotheby's Auction House)

Demantoid garnets' most famous source is Russia, but other localities such as Namibia, Afghanistan and Italy also produce gem-quality specimens of green andradite garnet. Stones are more typically unearthed in small sizes, making a majority of faceted products in very low carat weights. Large demantoid garnets can command high prices due to their rarity.

Gemcamp Laboratories

A Discovery Institute for Gemstones and Gemology

Our resident gemologists believe in encouraging public trust within the jewellery industry through shared education, value transparency and professionalism.


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