igneous
Quartz Vein in Basalt or Porphyry
Silicate-veined volcanic rock
Hardness varies from 7 for the quartz veins to 6 for the host rock, color is dark grey to black with contrasting pinkish-white quartz or feldspar veins, luster is dull to vitreous, cryptocrystalline to microcrystalline structure.
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Physical properties
Hardness varies from 7 for the quartz veins to 6 for the host rock, color is dark grey to black with contrasting pinkish-white quartz or feldspar veins, luster is dull to vitreous, cryptocrystalline to microcrystalline structure.
Formation & geological history
Formed via hydrothermal activity where mineral-rich fluids filled fractures in cooling volcanic or igneous rock, solidifying over millions of years.
Uses & applications
Used primarily for geological study, landscaping, and as decorative specimen pieces for rock collectors.
Geological facts
Veined rocks like this show the complex history of tectonic stress and fluid movement deep within the Earth's crust.
Field identification & locations
Easily identifiable in the field by contrasting light-colored mineral veins running through a darker matrix rock. Commonly found in coastal areas, riverbeds, and volcanic regions.
