Granite or Granitic Gneiss
Granitoid / Gneiss
Category
Browse igneous or sedimentary (anthropogenic modification) specimens identified by the Rock Identifier community.
Granite or Granitic Gneiss
Granitoid / Gneiss
Gneiss
Gneiss
Quartz Geode (with Calcite influence)
Silicon Dioxide (SiO2) with possible Calcium Carbonate (CaCO3)
Green Slag Glass
Amorphous Silicon Dioxide (with metallic impurities)
Possible tektite or iron-rich slag-like natural specimen
Uncertain; possibly natural glass (tektite) or magnetite-rich rock
Possible tektite or volcanic glass specimen
Natural silica glass; composition commonly near SiO₂, but exact identification requires chemical testing
Carnelian / Agate
Silicon Dioxide (SiO2) - Chalcedony
Gneiss
Metamorphic Gneiss
Quartz Geode
Silicon Dioxide (SiO2) - Crystalline Quartz
Epidote with Quartz Vein
Epidote-bearing metamorphic rock with quartz (Ca2(Al,Fe)3(SiO4)3(OH))
Gneiss with Quartz Vein
Gneiss containing Quartz (SiO2) filler
Gneiss
Gneiss (High-grade metamorphic rock)
Banded Gneiss
Gneiss (High-grade metamorphic rock)
Gneiss with Quartz Veining
Gneiss (High-grade Regional Metamorphic Rock)
Agate
Silicon Dioxide (Chalcedony variety), SiO2
Agate
Silicon Dioxide (Chalcedony), SiO2
Gneiss
Gneiss
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Gneiss
Gneiss (Metamorphic high-grade)
Gneiss
Gneiss (High-grade metamorphic rock)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Gneiss
Gneiss
Ruby in Zoisite
Anyolite (composite of Corundum Al2O3 and Zoisite Ca2Al3(SiO4)(Si2O7)O(OH))
Quartz Crystal (Geode Fragment)
Silicon Dioxide (SiO2)
Gneiss
Metamorphic Foliated Gneiss
Gneiss
Gneiss
Gneiss
High-grade regional metamorphic rock (Foliated)
Banded Gneiss
Gneiss
Concrete
Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)
Asphalt (Bituminous pavement)
Bituminous concrete / Asphalt
Concrete Fragment
Hardened Portland cement and mineral aggregate
Gneiss
Gneiss
Chalcedony
Chalcedony (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Chalcedony (Agate/Carnelian)
Silicon Dioxide (SiO2)
Gneiss
High-grade regional metamorphic rock (Foliated Gneiss)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Gneiss
Gneiss
Gneiss
Gneiss
Foliated Gneiss
Gneiss (Metamorphic Rock)
Gneiss
Gneiss
Agate
Silicon dioxide (chalcedony), SiO2