mineral
Tourmaline
(Na,Ca)(Al,Fe,Li)(Al,Mg,Mn)6(BO3)3Si6O18(OH,F)4
AI-generated identification · may be incorrectMohs hardness of 7 to 7.5, vitreous luster, prismatic crystal habit with striated faces, and conchoidal fracture.
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Physical properties
Mohs hardness of 7 to 7.5, vitreous luster, prismatic crystal habit with striated faces, and conchoidal fracture.
Formation & geological history
Forms in pegmatites and hydrothermal veins through high-temperature crystallization from cooling magma rich in water and boron.
Uses & applications
Used in high-end jewelry, piezoelectric pressure sensors, and sought after globally by mineral collectors.
Geological facts
Tourmaline exhibits strong pleochroism, often showing different colors when viewed from different angles.
Field identification & locations
Identified by its distinct triangular cross-section, vertical striations, and lack of cleavage; found worldwide in granitic pegmatites.
