igneous
Quartz-rich rock fragment
Likely iron-stained milky quartz, predominantly silicon dioxide (SiO₂); precise rock identification is uncertain from the image
AI-generated identification · may be incorrectOpaque white to translucent quartz with rusty brown iron-oxide staining and a vitreous to dull luster. Quartz has Mohs hardness 7, a trigonal crystal structure, no cleavage, and conchoidal fracture; the specimen appears only a few centimeters across.
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Physical properties
Opaque white to translucent quartz with rusty brown iron-oxide staining and a vitreous to dull luster. Quartz has Mohs hardness 7, a trigonal crystal structure, no cleavage, and conchoidal fracture; the specimen appears only a few centimeters across.
Formation & geological history
Quartz commonly forms as veins in cracks in igneous and metamorphic rocks, crystallizing from silica-rich fluids. The image cannot determine its age or exact geological setting.
Uses & applications
Common quartz is used in glass, electronics, and construction aggregate; small rough fragments are mainly collected as specimens.
Geological facts
The brown coloration is consistent with iron-oxide coatings or inclusions, rather than a separate metallic mineral.
Field identification & locations
Look for hardness sufficient to scratch glass, lack of cleavage, and irregular curved fracture surfaces; quartz veins occur worldwide. Confirm identification with a hardness or streak test if possible.
