Green Tourmaline

Green Tourmaline, traditionally called verdelite, is the green variety of tourmaline, usually the lithium-rich species elbaite. Its color ranges from light yellowish and grass green through rich emerald-like greens to dark bluish or olive tones.

The green color is caused mainly by iron, and sometimes by chromium or vanadium in the more vivid stones. Green tourmaline is one of the most abundant and affordable tourmaline colors, making it a popular and accessible gem.

It occurs as long prismatic crystals and is often found alongside other tourmaline colors, including in bicolor and watermelon crystals. Strong dichroism means the same stone can show two distinct green shades depending on viewing direction.

Green tourmaline forms in granitic pegmatites and in some metamorphic and hydrothermal settings, crystallizing from boron-rich fluids in open pockets. Iron incorporated into the structure produces most green coloration.

When chromium or vanadium replaces iron as the coloring agent, the result is the more intensely green chrome tourmaline, a distinct and pricier subtype.

Major sources include Brazil, Afghanistan, Pakistan, Madagascar, Nigeria, Mozambique, Tanzania, and the United States (Maine and California). Brazil and Africa supply most commercial green tourmaline.

Look for green prismatic crystals with a rounded triangular cross-section and strong lengthwise striations, classic tourmaline traits. Hardness is 7-7.5 with vitreous luster, white streak, and no cleavage.

Green tourmaline shows strong dichroism, often appearing darker green or bluish down the length of the crystal and lighter across it. This pleochroism helps separate it from emerald (hexagonal, weaker dichroism) and green glass (no dichroism).

Peridot is softer-looking and yellower-green with strong double refraction visible as doubled facet edges; tourmaline also doubles but is harder. Chrome tourmaline appears vivid grassy green and glows red under a Chelsea filter.

Green tourmaline is widely used in jewelry, faceted into rings, pendants, and earrings, and is valued for being a durable, affordable colored gem available in many shades. It is one of October's birthstone options alongside opal.

Crystal specimens, especially terminated green prisms and combinations with other colors, are collected. Value rises with the purity and saturation of the green and with clarity, with vivid chrome-colored material the most prized.

Metaphysically, green tourmaline is associated with the heart, vitality, and growth. These meanings are traditional rather than scientific.