mineral
White chalcedony (possibly milky quartz) cabochon
Chalcedony, microcrystalline SiO₂; appearance may also represent milky quartz or synthetic imitation
AI-generated identification · may be incorrectHardness about 6.5–7 Mohs; white, translucent to opaque, waxy-to-glassy luster, cryptocrystalline quartz with no visible cleavage. The smooth oval cabochon is polished and likely dyed-free, though visual identification alone is inconclusive.
Identified More mineral →
Explore White chalcedony (possibly milky quartz) cabochon in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 6.5–7 Mohs; white, translucent to opaque, waxy-to-glassy luster, cryptocrystalline quartz with no visible cleavage. The smooth oval cabochon is polished and likely dyed-free, though visual identification alone is inconclusive.
Formation & geological history
Forms when silica-rich groundwater deposits microcrystalline quartz in cavities and fractures, commonly in volcanic rocks; deposits range from Paleozoic to recent. This specimen has been cut and polished.
Uses & applications
Used for cabochon jewelry, beads, carvings, and ornamental objects; common-quality pieces have modest value.
Geological facts
Chalcedony is a quartz variety encompassing forms such as agate, jasper, and onyx. A conclusive identification requires testing because white glass, opalite, and ceramic imitations can look similar.
Field identification & locations
Common in Brazil, Uruguay, India, Madagascar, Turkey, and the western United States. Field clues include waxy luster, lack of cleavage, cool feel, and resistance to scratching by a steel knife; specific gravity is about 2.6.
