Rock Identifier
Milky quartz vein rock (Quartz, SiO₂; likely massive vein quartz with iron-oxide staining) — mineral
mineral

Milky quartz vein rock

Quartz, SiO₂; likely massive vein quartz with iron-oxide staining

AI-generated identification · may be incorrect

Hardness 7 Mohs; white to translucent gray with rusty tan-brown staining, vitreous to dull luster, and no cleavage. It has a trigonal crystal structure, though crystals are mostly massive and intergrown; specific gravity is about 2.65.

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Physical properties

Hardness 7 Mohs; white to translucent gray with rusty tan-brown staining, vitreous to dull luster, and no cleavage. It has a trigonal crystal structure, though crystals are mostly massive and intergrown; specific gravity is about 2.65.

Formation & geological history

Formed when silica-rich hydrothermal fluids filled fractures and crystallized as quartz veins, commonly during igneous or metamorphic activity. Its exact geological age cannot be determined from the photograph and depends on the host terrain.

Uses & applications

Used as aggregate, silica feedstock, ornamental stone, and a common mineral specimen; attractive translucent pieces may be polished, but this rough material has limited jewelry value.

Geological facts

The brown coloration is probably limonite or hematite coating and inclusions. Quartz can scratch ordinary glass and is much harder than calcite, a useful field distinction.

Field identification & locations

Common worldwide in exposed bedrock, pegmatites, hydrothermal veins, and metamorphic terrains. Look for glassy fracture, lack of cleavage, and resistance to scratching; a definitive identification may require hardness and acid tests.