Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
Category
Browse sedimentary rock or mineral (depending on origin and purity) specimens identified by the Rock Identifier community.
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide mixture)
Kyanite in Quartz
Kyanite (Al2SiO5) with Quartz (SiO2) matrix
Pink Granite
Granite (Phaneritic igneous rock rich in Orthoclase)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (Litharenite)
Sandstone (likely Graywacke or Arkosic varieties)
Arenite (composed primarily of SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Chert (Basanite variety)
Microcrystalline Quartz (SiO2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
Gneiss
Foliated Metamorphic Rock (Gneiss)
Sandstone (likely Quartzose Sandstone)
Arenite (SiO2 predominantly)
Slate
Foliated Metamorphic Rock (Mainly composed of Quartz, Illite, Chlorite)
Sandstone (with potential Arkose/Lithic characteristics)
Arenite (Sedimentary rock composed of sand-sized grains)
Gneiss
High-grade regional metamorphic rock (Foliated)
Quartz Vein in Host Rock
Quartz (SiO2) in Mafic or Sedimentary Matrix
Dendritic Jasper
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Magnetite
Magnetite (Fe3O4)
Sandstone (Calcareous Sandstone)
Calcareous Sandstone (primarily SiO2 with CaCO3 cement)
Sandstone (likely with Quartz Veining)
Arenite (primarily SiO2)
Diorite
Diorite (Intermediate intrusive igneous rock)
Scoria (Volcanic Rock)
Scoria (often basaltic scoria)
Blue Chalcedony (likely dyed Agate)
Silicon Dioxide (SiO₂)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Dalmatian Jasper
Dalmatian Stone (a microcrystalline quartz and feldspar rock with arfvedsonite)
Sandstone (with potential iron-oxide weathering)
Arenite (SiO2 based)
Opal
Hydrated Silica (SiO2·nH2O)
Clear Quartz
Silicon dioxide (SiO2)
Sandstone (with minor quartz and possible clay components)
Clastic Sedimentary Rock (SiO2 dominated)
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
Sandstone
Arenite (SiO2 based with quartz grains)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with FeO/Fe2O3)
Quartzite
Quartzite (primarily SiO2)
Limonite and Goethite encrusted Chert/Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)
Sandstone (likely River-tumbled Picture Sandstone)
Arenite (predominantly SiO2 with iron oxide impurities)
Gneiss (with Quartzite and Biotite)
Gneiss containing SiO2 (Quartz), K(Mg,Fe)3AlSi3O10(OH)2 (Biotite), and (K,Na,Ca)AlSi3O8 (Feldspar)
Unidentifiable Rock Fragment
Quartz
Quartz (SiO₂ - Silicon Dioxide)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Sandstone (Quartzite texture)
Arenite (SiO2 secondary)
Chert (or Flint)
SiO2 (predominantly microcrystalline quartz)