mineral
Tourmaline
Complex borosilicate mineral (e.g., Schorl: NaFe2+3Al6(Si6O18)(BO3)3(OH)4)
AI-generated identification · may be incorrectHardness 7-7.5 on Mohs scale, typically black to dark brown in this variety (schorl), vitreous luster, prismatic crystal structure with striated faces, and poor cleavage.
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Physical properties
Hardness 7-7.5 on Mohs scale, typically black to dark brown in this variety (schorl), vitreous luster, prismatic crystal structure with striated faces, and poor cleavage.
Formation & geological history
Forms in pegmatites, hydrothermal veins, and metamorphic rocks under high temperature and pressure conditions.
Uses & applications
Used in fine jewelry, piezoelectric devices, pressure sensors, and as sought-after mineral specimens for collectors.
Geological facts
Tourmaline exhibits pyroelectric and piezoelectric properties, meaning it can generate an electrical charge when heated or subjected to pressure.
Field identification & locations
Identify by its characteristic triangular cross-section, striated prismatic crystals, and lack of good cleavage. Commonly found worldwide, especially in Brazil, Madagascar, and the USA.
