Greenstone
Metamorphosed Mafic Igneous Rock
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Greenstone
Metamorphosed Mafic Igneous Rock
Garnet (Red Garnet)
Garnet Group. The red varieties seen in jewelry are typically Almandine (Fe3Al2(SiO4)3), Pyrope (Mg3Al2(SiO4)3), or a mix of the two (pyrope-almandine series).
Sandstone
Arenite
Sandstone
Arenite (primarily SiO2)
Turquoise (Green variety)
Hydrous phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Coquina / Shelly Limestone
Coquina (Biogenic Limestone)
Chert (Flint nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pyrite in Matrix (Quartz/Schist)
Iron Sulfide (FeS2)
Leopard Skin Jasper
Jasper (Silicon Dioxide with impurities), SiO2
Sandstone (Red)
Arenite (Fe2O3 heavy)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
Sandstone
Arenite (SiO2 predominantly)
Fossiliferous Brachiopod in Shale
Brachiopoda (Phylum) preserved in Carbonaceous Shale
Limonite (Iron Ore)
Limonite (an FeO(OH)·nH2O mineraloid, not a true mineral due to variable composition)
Sandstone
Arenite or Sandstone
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert Nodule (Flint)
Chert (Cryptocrystalline Silica - SiO2)
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
Travertine
Travertine (CaCO3 - Calcium Carbonate)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Bauxite
Bauxite (Mixture of Hydrous Aluminum Oxides)
Blue Kyanite
Kyanite (Al2SiO5)
Sandstone (with potentially metamorphic or basaltic bands)
Arenite / Lithic Wacke
Banded Chert
Chert (a microcrystalline variety of quartz, SiO2 with minor impurities)
Quartz (Pebble)
Quartz (SiO₂)
Chert (Yellow Jasper)
Microcrystalline Quartz (SiO2)
Fossil Shell (Bivalve)
Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Rough Agate/Chert Nodules
Cryptocrystalline Quartz (SiO2)
Granitic Gneiss
Gneiss (Metamorphic Rock)
Garnet Schist
Almandine Garnet in Mica Schist (Fe3Al2(SiO4)3)
Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Folded Schist / Gneiss (Metamorphic Rock)
Regional Metaphoric Folded Outcrop (predominantly Schist/Gneiss)
Shale
Fissile Mudstone (primarily composed of clay minerals and quartz grains)
Limonite-stained Chert
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)