mineral

Green Tourmaline

Verdelite (Silicate mineral); Na(Li,Al)3Al6(BO3)3Si6O18(OH)4

Hardness: 7-7.5 on the Mohs scale. Color: Pale green to forest green. Luster: Vitreous (glassy). Crystal structure: Trigonal/Hexagonal elongated prisms with vertical striations. Cleavage: Indistinct. Specific gravity: 3.06.

Hardness: 7-7
Color: Pale green to forest green
Luster: Vitreous (glassy)

Identified March 14, 2026More mineral →

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Physical properties

Formation & geological history

Formed in granitic pegmatites and metamorphic rocks like schist and marble through hydrothermal processes. Most specimens date from the Phanerozoic eon down to recent geological eras, depending on the host rock formation.

Uses & applications

Used primarily in high-end jewelry as a gemstone, as a specimen for mineral collectors, and historically in scientific instruments due to its piezoelectric properties.

Geological facts

Green tourmaline is often called 'Verdelite'. It is unique because it is pleochroic, meaning it can show different shades of color when viewed from different angles. It also possesses pyroelectricity, becoming electrically charged when heated.

Field identification & locations

Identify in the field by its long, columnar crystal habit and the presence of fine parallel ridges (striations) along the length of the crystal. Commonly found in Brazil, Afghanistan, Pakistan, and Maine/California in the USA.

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Mineral/Rock

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