mineral
Tourmaline
Schorl, NaFe2+3Al6(Si6O18)(BO33)(OH4)
AI-generated identification · may be incorrectMohs hardness 7 to 7.5, black color, vitreous to submetallic luster, trigonal crystal system with striated prismatic crystals, conchoidal fracture.
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Physical properties
Mohs hardness 7 to 7.5, black color, vitreous to submetallic luster, trigonal crystal system with striated prismatic crystals, conchoidal fracture.
Formation & geological history
Forms in pegmatites, hydrothermal veins, and metamorphic rocks through high-temperature crystallization from boron-rich fluids.
Uses & applications
Used in mineral specimen collecting, jewelry, and industrial applications due to its piezoelectric and pyroelectric properties.
Geological facts
Tourmaline exhibits pyroelectricity, meaning it can generate an electrical charge when heated or cooled.
Field identification & locations
Identified by its characteristic triangular cross-section and distinct vertical striations on the crystal faces; found worldwide.
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Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Granite
Granite (Phaneritic intrusive igneous rock)
igneous