gemstone
Blue Topaz
Al2SiO4(F,OH)2
AI-generated identification · may be incorrectHardness of 8 on the Mohs scale, vitreous luster, orthorhombic crystal system, and distinct basal cleavage. Colors range from pale sky blue to deep London blue, often achieved via irradiation and heat treatment.
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Physical properties
Hardness of 8 on the Mohs scale, vitreous luster, orthorhombic crystal system, and distinct basal cleavage. Colors range from pale sky blue to deep London blue, often achieved via irradiation and heat treatment.
Formation & geological history
Forms in pegmatites, high-temperature hydrothermal veins, and granite cavities through fluorine-bearing vapor activity during the final stages of igneous crystallization.
Uses & applications
Extensively used in fine jewelry for rings, pendants, and earrings due to its durability and brilliant clarity.
Geological facts
Natural blue topaz is extremely rare; most commercial blue topaz is produced by treating colorless stones with radiation and heat. Topaz is the birthstone for December.
Field identification & locations
Easily identified by its high Mohs hardness of 8, perfect basal cleavage, and cool touch. Major deposits are found in Brazil, Nigeria, Sri Lanka, and the US.
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