mineral
Milky quartz vein in altered host rock
Quartz (SiO₂), likely with feldspar, mica, and iron-oxide alteration
AI-generated identification · may be incorrectWhite to translucent quartz has a vitreous-to-waxy luster, uneven fracture, and Mohs hardness 7; the greenish-gray host appears finer-grained and altered, with brown iron-oxide staining. Quartz is trigonal and lacks cleavage, while feldspar or mica in the host may show cleavage.
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Physical properties
White to translucent quartz has a vitreous-to-waxy luster, uneven fracture, and Mohs hardness 7; the greenish-gray host appears finer-grained and altered, with brown iron-oxide staining. Quartz is trigonal and lacks cleavage, while feldspar or mica in the host may show cleavage.
Formation & geological history
Likely formed when silica-rich hydrothermal fluids filled fractures in older igneous or metamorphic rock; the exact age and locality cannot be determined from the image. Iron oxidation produced the brown staining and weathered surface.
Uses & applications
Quartz specimens are collected, and quartz is used in glass, abrasives, electronics, and engineered stone; the host rock has little construction value unless present in large, sound masses.
Geological facts
Milky quartz becomes opaque because microscopic fluid inclusions and defects scatter light. The specimen is more accurately called a quartz vein or quartz-rich breccia than a single pure mineral sample.
Field identification & locations
Identify it by its white glassy quartz, hardness, lack of cleavage, and inability to scratch with a steel knife while potentially scratching glass; the green-gray matrix may indicate chlorite- or epidote-rich alteration. Common in hydrothermal veins worldwide.
