Mica Schist
Mica Schist (primarily Muscovite and Biotite composition)
metamorphic
Category
Industrial Byproduct (Anthropogenic Rock)
Browse industrial byproduct (anthropogenic rock) specimens identified by the Rock Identifier community.
Learn about Industrial Byproduct (Anthropogenic Rock) in the encyclopedia
View all →
Basalt
Mafic volcanic rock (dominated by Plagioclase and Pyroxene)
igneous
Veined Pebble (likely a Quartz-Veined Pebble)
Pebble with Mineral Vein (e.g., Quartz Vein in a Chert/Mudstone Pebble)
Sedimentary Rock (possibly conglomerate or breccia with a quartz vein)
Coral Fossil
Anthozoa (Scleractinia)
fossil
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
mineraloid / anthropogenic (man-made origin)
Quartzite
Quartzite (SiO2)
metamorphic
Rough Blue Sapphire
Corundum (Al2O3)
mineral
Tumbled blue-green stone, likely aquamarine-bearing pegmatite or blue apatite
Probable fluorapatite, Ca5(PO4)3(F,Cl,OH), though visual identification is uncertain
mineral
Granite
Phaneritic Plutonic Felsic Rock
igneous
Porphyritic Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Yellow Quartz (Citrine/Quartzite Pebble)
Silicon Dioxide (SiO2)
mineral
Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Quartz (Sunstone-like Chalcedony)
Silicon Dioxide (SiO2)
mineral
Ironstone (with Limonite/Goethite)
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O and Hematite Fe2O3)
sedimentary
Mica Schist
Mica Schist (primarily Muscovite and Biotite composition)
metamorphic
Shale or Siltstone
Sedimentary Clastic Rock (Variable mineral composition including quartz and clay minerals)
sedimentary
Iron-rich meteorite candidate
Unclassified iron meteorite or stony-iron meteorite; confirmation requires chemical and nickel testing
meteorite
Quartz Pebble (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
mineral
Diabase (Greenstone)
Diabase (also known as Dolerite)
igneous
Blue Sapphire Crystal (Rough)
Corundum (Aluminum Oxide, Al2O3)
mineral
Green Apophyllite and Stilbite on Quartz Cluster
Apophyllite-(K) (KCa4(Si8O20)(F,OH)·8H2O), Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O), Quartz (SiO2)
Mineral
Quartz Vein in Schist / Gneiss
Silicon Dioxide (SiO2) in Metamorphic Matrix
igneous
Red Sandstone
Arenite (Fe2O3 rich)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
Mineral/Sedimentary
Quartzite
Quartzite (composed primarily of SiO2)
metamorphic
Quartz / Common Opal Transition
Silicon Dioxide (SiO2)
mineral
Quartzite (River Pebble)
Metamorphic rock consisting primarily of Quartz (SiO2)
metamorphic
Coal (Bituminous or Anthracite)
Carbonaceous sedimentary rock (primarily Carbon, C)
sedimentary
Agate (Thunderegg segment)
Silicon dioxide (SiO2) - Microcrystalline Quartz/Chalcedony
mineral
Diamond in Kimberlite
Diamond (C in Kimberlite Matrix)
igneous
Beryl (Emerald variety in host rock)
Be3Al2(SiO3)6 (Silicate mineral)
mineral
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic
Garnet-Bearing Schist
Almandine Garnet Micaceous Schist
metamorphic
Basalt with Sulfide/Pyrite inclusion
Aphanitic Mafic Igneous Rock (likely Basalt) with Pyrite (FeS2)
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Pearls
Pearl: biomineralized aragonite (CaCO₃) and conchiolin
gemstone
Quartzite with Quartz Veining
Quartzite (primarily SiO2)
metamorphic
Quartzite Pebble
Quartzite (SiO2 with minor impurities)
metamorphic
Agate
Chalcedony (SiO2) with impurities
sedimentary