gemstone
Ruby (Cabochon)
Corundum (Al2O3)
Hardness of 9 on the Mohs scale, deep red color caused by chromium impurities, vitreous to adamantine luster, trigonal crystal system, lacks cleavage with distinct parting.
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Physical properties
Hardness of 9 on the Mohs scale, deep red color caused by chromium impurities, vitreous to adamantine luster, trigonal crystal system, lacks cleavage with distinct parting.
Formation & geological history
Formed in metamorphic or igneous rocks such as marble, basalt, or gneiss, where aluminum-rich rocks undergo high-temperature, high-pressure metamorphism.
Uses & applications
Primarily used in high-end fine jewelry, laser technology, and precision watch bearings.
Geological facts
Ruby is one of the most historically prized gemstones, often associated with passion, protection, and wealth. The red color comes from trace amounts of chromium.
Field identification & locations
Can be identified in the field by its exceptional hardness (scratching quartz and topaz), high density, and characteristic red fluorescence under ultraviolet light.
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