mineral
Tumbled milky quartz or pale chalcedony
Quartz, SiO₂; possibly microcrystalline quartz (chalcedony)
AI-generated identification · may be incorrectTranslucent cream-white body with a vitreous to waxy luster and brown inclusions or surface staining; Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65. The rounded shape indicates tumbling or natural abrasion.
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Physical properties
Translucent cream-white body with a vitreous to waxy luster and brown inclusions or surface staining; Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65. The rounded shape indicates tumbling or natural abrasion.
Formation & geological history
Quartz forms in silica-rich hydrothermal veins, cavities, and sedimentary environments; chalcedony commonly develops by silica deposition in volcanic cavities. Quartz is abundant from Precambrian to modern geological settings.
Uses & applications
Used as an inexpensive ornamental stone, lapidary material, paper or glass abrasive, and collector specimen; this small piece has little jewelry value unless unusually clear or patterned.
Geological facts
The brown areas may be iron-oxide staining, included matrix, or minor limonite. A steel file should not easily scratch quartz, while quartz can scratch ordinary glass.
Field identification & locations
Common worldwide, especially in Brazil, Madagascar, India, Mexico, and the United States. Confirm with a scratch test on an inconspicuous area, checking that it does not scratch easily and shows no obvious cleavage.
