mineral/igneous

Quartz Vein in Host Rock

Silicon Dioxide (SiO2) in matrix

Hardness: 7 (Mohs), Color: Milky white to translucent quartz in brown/tan host rock, Luster: Vitreous to greasy, Crystal structure: Trigonal (hexagonal prisms), Cleavage: None (conchoidal fracture)

Identified June 6, 2026More mineral/igneous →

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Physical properties

Hardness: 7 (Mohs), Color: Milky white to translucent quartz in brown/tan host rock, Luster: Vitreous to greasy, Crystal structure: Trigonal (hexagonal prisms), Cleavage: None (conchoidal fracture)

Formation & geological history

Formed from hydrothermal fluids rich in silica circulating through fractures in the earth's crust. As the fluids cool or pressure drops, the quartz precipitates and fills the cracks, creating veins.

Uses & applications

Industrial source of silica, specimen collecting, and potentially an indicator for precious metals like gold in certain geological settings.

Geological facts

Quartz veins are one of the most common ways that gold is transported and deposited in the crust. This specimen shows a thick vein of 'milky quartz' which gets its color from tiny fluid inclusions trapped during growth.

Field identification & locations

Identified by the distinct contrast between the white crystalline quartz and the duller host rock. Hardness is a key identifier; it will easily scratch glass. Commonly found in mountainous or volcanic regions.

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SiO2 (Quartz) with associated ferromagnesian minerals

Mineral/Igneous/Metamorphic association

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FeS2 (Iron Pyrite) with SiO2 (Quartz)

Mineral/Igneous/Hydrothermal

Labradorite (likely Black Labradorite or Larvikite)

Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.

Mineral/Igneous Rock

Amethyst Geode

Quartz (SiO₂) with iron impurities

Mineral/Igneous (secondary formation)

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

mineral

Basalt

Igneous