Magnetite / Ironstone
Iron(II,III) oxide (Fe3O4)
Category
Browse sedimentary or igneous (host environment) specimens identified by the Rock Identifier community.
Magnetite / Ironstone
Iron(II,III) oxide (Fe3O4)
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Chert (Flint)
Chert (microcrystalline quartz)
Rose Quartz
Silicon Dioxide (SiO2) with traces of titanium, iron, or manganese
Prase Quartz on Feldspar
Quartz (Silicon Dioxide, SiO2) with Hedenbergite inclusions on Potassium Feldspar (KAlSi3O8)
Basalt (Weathered Pebble)
Extrusive mafic igneous rock; minerals primarily Plagioclase feldspar and Pyroxene
Quartz (Grain/Pebble)
Silicon Dioxide (SiO2)
Basalt River Pebble
Mafic volcanic rock (Basalt)
Agate
Silicon Dioxide (SiO2) - Chalcedony variety
Agate
Agate (Microcrystalline Quartz, SiO2)
River Rock (Granite Cobble)
Granite (Phaneritic Quartz-Feldspar-Mica intrusive rock)
Greenschist (containing Epidote and Quartz)
Greenschist (Epidote-Chlorite-Actinolite Schist)
Marcasite Concretion (Propeller/Sand Dollar shape)
Marcasite (FeS2)
Chalcedony (Agate/Carnelian type)
Silicon Dioxide (SiO2)
Amber
Succinite (fossilized tree resin)
Quartz (Milky or Yellow variety)
Silicon Dioxide (SiO2)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Hematite
Hematite, Iron(III) oxide (Fe2O3)
Agate (Dyed High-Grade Polished Slice)
Silicon dioxide (SiO2), Chalcedony crystal variety
Sandstone
Arenite (primarily SiO2 with various cementing agents)
Sandstone (Calcareous Sandstone)
Calcareous Sandstone (primarily SiO2 with CaCO3 cement)
Pyrite
Iron Sulfide (FeS2)
Turquoise
Hydrous phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Moss Agate
Silicon Dioxide with inclusions (SiO2 + impurities)
Basalt River Pebble
Basalt
Granite Cobble
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
Quartz Geode
Quartz (SiO2) within a geode structure
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Quartz (White or Milky Quartz Pebble)
Quartz (Silicon Dioxide, SiO2)
Quartz Druze on Matrix
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Specular Hematite
Hematite (Fe2O3)
Calcite
Calcium Carbonate (CaCO3)
Milky Quartz Pebble with Chert
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Sandstone (Ferruginous)
Arenite (Fe-rich)
Green Opal
Hydrated Silica (SiO2·nH2O)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Rough Quartz (likely Rose or Amethyst variety)
Silicon Dioxide (SiO2)