metamorphic
Likely quartz-rich rock (possibly milky quartz or quartzite)
Quartz-rich aggregate, predominantly silicon dioxide (SiO₂); exact identification is uncertain from the image
AI-generated identification · may be incorrectWhite to pale gray, rough and granular with a dull to vitreous luster. Quartz has Mohs hardness 7, no cleavage, and a hexagonal crystal structure; the rock’s hardness depends on its other minerals.
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Physical properties
White to pale gray, rough and granular with a dull to vitreous luster. Quartz has Mohs hardness 7, no cleavage, and a hexagonal crystal structure; the rock’s hardness depends on its other minerals.
Formation & geological history
Could be quartzite formed when sandstone was metamorphosed, or a massive quartz vein formed from silica-rich fluids. Age and origin cannot be determined from appearance alone.
Uses & applications
Quartzite is used as construction aggregate, paving stone, and sometimes dimension stone; attractive quartz specimens are collected or used decoratively.
Geological facts
A glass-scratch test can help distinguish hard quartz-rich material from softer rocks, but it is not definitive and may damage the specimen.
Field identification & locations
Look for interlocking or fused quartz grains and a scratch-resistant surface; quartzite is common in many metamorphic terrains, while massive quartz occurs in veins worldwide. A closer view or hardness test is needed for confident identification.
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