Chrome Tourmaline

Chrome Tourmaline is a vividly green tourmaline whose color comes from chromium and vanadium rather than the iron that colors ordinary green tourmaline. This gives it an intense, saturated grass-to-emerald green that rivals fine emerald and tsavorite garnet.

Mineralogically it is often dravite or elbaite, distinguished from common green tourmaline by its chromophore chemistry. Because chromium-bearing tourmaline is geologically uncommon, chrome tourmaline is rarer and more valuable than typical green tourmaline.

The main source is East Africa, especially Tanzania and Kenya, near the same regions that produce tsavorite garnet. Stones are usually small because large clean crystals are scarce.

Chrome tourmaline forms where tourmaline-producing boron-rich fluids interact with rocks rich in chromium and vanadium, an uncommon pairing. This typically occurs in metamorphic environments rather than the classic lithium pegmatites that yield most gem tourmalines.

The chromium and vanadium substitute into the crystal structure to produce the intense green, the same elements that color emerald and tsavorite garnet, which is why these gems often come from related geological settings.

The principal sources are Tanzania (notably around the Umba Valley and Landanai) and Kenya in East Africa.

Look for an intensely saturated grass-to-emerald green tourmaline, more vivid than ordinary iron-colored green tourmaline. Crystals show the rounded triangular cross-section and lengthwise striations of tourmaline. Hardness is 7-7.5 with vitreous luster, white streak, and no cleavage.

A hallmark test is that chrome tourmaline glows red or pink under a Chelsea filter and shows a chromium absorption spectrum, like emerald and tsavorite, whereas iron-colored green tourmaline does not.

It shows strong dichroism. Distinguish it from emerald (hexagonal beryl) and tsavorite garnet (isometric, singly refractive, no dichroism) by crystal form and optical behavior.

Chrome tourmaline is a prized jewelry gemstone, faceted into rings, pendants, and earrings, valued for its vivid emerald-like green at a generally lower price than emerald. Because clean material is usually small, larger fine stones command strong premiums.

It is also collected by connoisseurs who appreciate its rarity among tourmalines. Value depends overwhelmingly on the intensity of the green, then clarity and size.

Metaphysically, chrome tourmaline is associated with the heart, abundance, and vitality, like other green stones. These meanings are traditional rather than scientific.