mineral

Green Tourmaline (Verdelite)

Elbaite (Complex Borosilicate: Na(Li,Al)3Al6(BO3)3Si6O18(OH)4)

Hardness: 7-7.5 (Mohs); Color: Emerald green to olive; Luster: Vitreous; Crystal Structure: Trigonal (often long prismatic with vertical striations); Cleavage: Indistinct; Specific Gravity: 3.0-3.3

Hardness: 7-7
Color: Emerald green to olive
Luster: Vitreous

Identified March 15, 2026More mineral →

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Physical properties

Hardness: 7-7.5 (Mohs); Color: Emerald green to olive; Luster: Vitreous; Crystal Structure: Trigonal (often long prismatic with vertical striations); Cleavage: Indistinct; Specific Gravity: 3.0-3.3

Formation & geological history

Formed primarily in granitic pegmatites via hydrothermal processes where boron and other rare elements concentrate during the final stages of magma crystallization. They occur in environments ranging from Precambrian to more recent geological ages.

Uses & applications

Predominantly used as a high-quality gemstone in jewelry and by mineral collectors for crystal specimens. Industrially, its piezoelectric and pyroelectric properties have been used in pressure gauges and older electronics.

Geological facts

Tourmaline is unique because it can become electrically charged when heated (pyroelectricity) or squeezed (piezoelectricity). It is often called the 'chameleon of gemstones' due to its vast range of colors.

Field identification & locations

Identify in the field by its characteristic long, slender needle-like crystals with rounded triangular cross-sections and distinct vertical striations along the sides. Common locations include Brazil, Afghanistan, Namibia, and the USA (Maine and California).

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