mineral
Tumbled Black Tourmaline
Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)4)
Hardness of 7 to 7.5 on the Mohs scale, black color, vitreous to submetallic luster, trigonal crystal system, conchoidal fracture with no true cleavage, and specific gravity of approximately 3.0 to 3.2.
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Physical properties
Hardness of 7 to 7.5 on the Mohs scale, black color, vitreous to submetallic luster, trigonal crystal system, conchoidal fracture with no true cleavage, and specific gravity of approximately 3.0 to 3.2.
Formation & geological history
Forms primarily in pegmatites, hydrothermal veins, and metamorphic rocks such as schists and gneisses through high-temperature crystallization from boron-rich fluids.
Uses & applications
Used widely in jewelry, metaphysical healing and grounding practices, and as a mineral specimen for collectors.
Geological facts
Black tourmaline, or schorl, is the most common variety of tourmaline, accounting for about 95% of all tourmaline in nature. It is naturally piezoelectric and pyroelectric.
Field identification & locations
Easily identified by its dark black color, high hardness, and lack of distinct cleavage. It is commonly sourced from Brazil, Pakistan, Madagascar, and the United States.
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