Clear Quartz Crystal
Quartz (Silicon Dioxide, SiO2)
Category
Browse igneous or sedimentary (anthropogenic modification) specimens identified by the Rock Identifier community.
Clear Quartz Crystal
Quartz (Silicon Dioxide, SiO2)
Gneiss
Gneiss
Milky Quartz
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade regional metamorphic rock)
Gneiss (specifically Granitic Gneiss)
Gneiss
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
White Agate (Chalcedony)
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Pyrite (on the right) and Magnetite or Hematite (on the left)
Iron Sulfide (FeS2) and Iron Oxide (Fe3O4 or Fe2O3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz (Peach/Orange variety)
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Pink Calcite (Mangano Calcite)
Calcium Carbonate (CaCO3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Gneiss (specifically Granite Gneiss)
Gneiss (High-grade Regional Metamorphic Rock)
Milky Quartz
Silicon Dioxide (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Calcite
Calcium Carbonate (CaCO3)
Specular Hematite
Hematite (Fe2O3)
Carnelian Agate
Carnelian (Silicon Dioxide - SiO2)
Clear Quartz Crystal Cluster
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Gneiss
Gneiss
Biotite (Black Mica)
Biotite - K(Mg,Fe)3AlSi3O10(F,OH)2
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Quartz Pebble
Silicon Dioxide (SiO2)
Gneiss
High-grade metamorphic rock (Gneiss)
Polished dark pebble, possibly basalt or chert
Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or microcrystalline silica (chert)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Quartz Pebble
Silicon Dioxide (SiO2)
Milky quartz (quartz-rich fragment)
Quartz, silicon dioxide (SiO₂)
Basalt pebble
Basalt; primarily plagioclase feldspar, pyroxene, and often olivine
Tumbled Hematite
Hematite (Alpha iron oxide, Fe2O3)
Rounded dark pebble, likely basaltic andesite
Fine-grained mafic volcanic rock; probable basalt or andesite, identification uncertain from image alone
River Stone (likely Andesite or Siltstone)
Intermediate Volcanic Rock / Fine-grained Sedimentary Rock
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Agate
Silicon dioxide (Chalcedony), SiO2
Quartz Pebble
Silicon Dioxide (SiO2)
Vesicular basalt (likely weathered lava rock)
Basalt; fine-grained mafic volcanic rock composed chiefly of plagioclase, pyroxene, and commonly olivine
Clear quartz crystal
Quartz (silicon dioxide, SiO₂)