Green Garnet

Green Garnet is a collective trade name covering any garnet whose color falls in the green range. The most important are tsavorite (a chromium- and vanadium-colored grossular), demantoid (an iron- and chromium-colored andradite famous for fire), and uvarovite (a chromium-rich, usually tiny crystal).

Unlike most green gems, garnets are singly refractive and never show the doubling seen in tourmaline or peridot. Their color is purely a body color from trace transition metals, so fine specimens can rival emerald in saturation while remaining free of the inclusions that plague beryl.

Green garnet is comparatively rare, which keeps clean stones over a few carats expensive, especially demantoid with its diamond-like dispersion.

Green grossular (tsavorite) forms in metamorphosed impure limestones and skarns where calcium-rich sediments are recrystallized at moderate temperatures, picking up traces of chromium and vanadium from associated rocks. The Mozambique metamorphic belt of Kenya and Tanzania is the classic source.

Demantoid (andradite) crystallizes in serpentinites and contact-metamorphic skarns, where iron and chromium supply both its green color and dispersive fire; the Ural Mountains of Russia and Namibia are key deposits.

Uvarovite grows as drusy crusts on chromite ore in ultramafic rocks. All garnets are products of relatively high-temperature, high-pressure metamorphic or contact environments rather than slow cavity growth.

Look for a glassy to slightly resinous luster, a hardness of about 7, and no double refraction. A garnet's single refraction distinguishes it from peridot and tourmaline, which show visible doubling of back facets.

The streak is white. Tsavorite tends to be a pure to bluish-green and stays clean; demantoid shows extreme fire (dispersion higher than diamond) and may contain the diagnostic radiating 'horsetail' chrysotile inclusions. Uvarovite occurs as tiny emerald-green crystals too small to facet, usually as drusy clusters.

Look-alikes include emerald (doubly refractive, more included), green tourmaline (doubly refractive, dichroic), and chrome diopside (softer, ~5.5, with cleavage). Garnet lacks cleavage and chips conchoidally.

Green garnet is almost entirely a jewelry stone. Tsavorite is a leading emerald alternative, prized for brilliance, durability, and lack of treatment. Demantoid is a connoisseur's collector gem commanding very high prices for its fire, particularly Russian material with horsetail inclusions.

Uvarovite drusy is set as crusted clusters or cabochons because individual crystals are minute. Larger faceted green garnets are used in rings, pendants, and earrings.

Metaphysically, green garnet is associated with abundance, vitality, and heart-centered renewal, though these claims are not scientific. Its main value remains its rarity and untreated natural color.