Sandstone (Quartz Arenite)
Sandstone (SiO2 with possible mineral cements)
sedimentary
Category
Metamorphic (Likely Gneiss Or Schist Based On Texture)
Browse metamorphic (likely gneiss or schist based on texture) specimens identified by the Rock Identifier community.
Anthracite Coal
Anthracite (Carbon-based sedimentary-metamorphic rock)
metamorphic
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Greenstone (Epidisite / Chlorite Schist)
Metabasalt (often contains Epidote Ca2Al2(Fe3+,Al)(SiO4)(Si2O7)O(OH) and Chlorite)
metamorphic
Greenstone (Greywacke or Nephrite Jade variant)
Metamorphosed mafic igneous or sedimentary rock (e.g., Actinolite-Chlorite Schist)
metamorphic
Tanzanite
Blue Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Sapphire
Corundum (Al2O3)
Mineral
Pink Feldspar (Orthoclase)
Orthoclase Feldspar (KAlSi3O8)
mineral
Sandstone
Arenite
sedimentary
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Quartzite Cobble with Quartz Vein
Metamorphic Quartzite (SiO2)
metamorphic
Sandstone (Quartzite Pebble)
Arenite / Metamorphosed Sandstone (SiO2)
sedimentary
Nuummite
Nuummite (Orthorhombic amphiboles: Anthophyllite and Gedrite)
metamorphic
Kyanite
Kyanite (Al2SiO5)
mineral
Aquamarine
Beryl (Be3Al2Si6O18 with iron traces)
mineral
Emerald in Matrix
Beryl (Be3Al2Si6O18) containing Chromium/Vanadium impurities
mineral
Phyllite
Phyllite (Foliated metamorphic rock)
metamorphic
Quartzite
Quartzite (mostly SiO2)
metamorphic
Quartz
Silicon Dioxide (SiO2)
Mineral
Rhyolitic Tuff
Rhyolitic Tuff / Pyroclastic rock
igneous
Sandstone (River Cobble)
Clastic sedimentary rock (primarily SiO2 with various lithic fragments)
sedimentary
Green Aventurine (Tumbled Quartz)
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)3Si3O10(OH)2)
metamorphic
Fossilized Coral (Petoskey Stone or similar Favosites)
Hexagonaria percarinata / Favosites (Silurian-Devonian Coral)
sedimentary
Yellow Quartzite (River Pebble)
Quartzite (primarily SiO2 with iron oxide inclusions)
metamorphic
Basalt with Iron Oxidation (Lattice/Veined)
Mafic Volcanic Rock (principally Plagioclase and Pyroxene)
igneous
Mica Schist
Medium-grade regional metamorphic rock (composition varies)
metamorphic
Quartz
Silicon Dioxide (SiO₂)
Mineral
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Sedimentary Rock
Dumortierite Quartz
Al7BO3(SiO4)3O3 (Aluminum borate silicate)
mineral
Quartzite Cobble
Quartzite (primarily SiO2)
metamorphic
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
mineral
Magnetite
Magnetite (Fe3O4)
mineral
Sandstone (likely Siltstone)
Arenite or Siltstone (high SiO2 content)
sedimentary
Fuchsite (Green Muscovite)
K(Al,Cr)2(AlSi3O10)(OH)2
mineral
Quartzite Pebbler
Quartzite (primarily SiO2)
metamorphic
Ferro-silicate Slag
Industrial Vitrified Slag (High-silica amorphous glass)
Mineral byproduct (Anthropogenic)
Anthracite Coal
Anthracite (Carbon-based solid)
metamorphic
Greenstone (Epidote/Chlorite Schist)
Metabasalt (composed primarily of Epidote Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH) and Chlorite (Mg,Fe)3(Si,Al)4O10(OH)2·(Mg,Fe)3(OH)6)
metamorphic
Quartzite (River Cobble)
Quartzite (primarily SiO2)
metamorphic
Ruby (Corundum)
Aluminum Oxide (Al2O3) with Chromium traces
mineral
Ruby
Corundum (Al2O3 with Chromium impurities)
mineral