metamorphic
Quartz-bearing altered rock, likely quartzite or hydrothermal quartz vein
Predominantly quartz (SiO₂), with possible chlorite/serpentine and iron-oxide alteration
AI-generated identification · may be incorrectWhite to pale gray, massive to sugary crystalline texture with green-gray matrix; vitreous to dull luster, no obvious cleavage, Mohs hardness about 7, and specific gravity near 2.65. The specimen appears weathered and fractured, with milky quartz-rich zones.
Identified More metamorphic →
Explore Quartz-bearing altered rock, likely quartzite or hydrothermal quartz vein in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
White to pale gray, massive to sugary crystalline texture with green-gray matrix; vitreous to dull luster, no obvious cleavage, Mohs hardness about 7, and specific gravity near 2.65. The specimen appears weathered and fractured, with milky quartz-rich zones.
Formation & geological history
Likely formed when silica-rich hydrothermal fluids filled fractures, or when quartz-rich sandstone recrystallized during metamorphism; the green coloration may reflect chlorite or other alteration minerals. Exact geological age and locality cannot be determined from the image.
Uses & applications
Used mainly as a teaching or collector specimen; quartzite can serve as crushed aggregate, building stone, or decorative stone, while attractive quartz specimens may be polished.
Geological facts
Quartz commonly forms interlocking crystals and breaks conchoidally rather than along cleavage planes. Green-gray coloration is not diagnostic and may require hardness, streak, acid, or thin-section testing for identification.
Field identification & locations
Look for quartz scratching glass, a white streak, translucent milky areas, and absence of carbonate fizz in dilute acid. Common in hydrothermal vein districts and metamorphic terrains; approximate value is $5–$30 for a typical hand specimen, or $30–$100 if crystals and locality are attractive.
More like this
