Greenstone
Greenschist
metamorphic
Category
Not A Natural Rock (Man Made Composite)
Browse not a natural rock (man made composite) specimens identified by the Rock Identifier community.
Chert (Cherty Shale / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Ruby in Zoisite
Ruby (Corundum, Al2O3) in Zoisite (Calcium aluminum silicate hydroxide, Ca2Al3(SiO4)3(OH)) with some Hornblende
Metamorphic Rock (specifically a rock composed of minerals)
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Serpentinite (Serpentine Rock)
Primarily composed of serpentine group minerals, such as antigorite, chrysotile, and lizardite. Chemical formula for serpentine minerals is (Mg,Fe)3Si2O5(OH)4.
Metamorphic
Bituminous Coal
Organic Sedimentary Rock (composed mostly of carbon with sulfur and hydrogen)
sedimentary
Hematite
Iron(III) oxide (Fe2O3)
mineral
Sandstone
Arenite
sedimentary
Quartz Geode/Druzy Quartz
Quartz (SiO₂)
Mineral
Dalmatian Stone
Dalmatian Jasper (Aplitic Perthite)
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Basalt with Caliche
Extrusive Mafic Igneous Rock with Secondary Carbonate Crust
igneous
Druzy Quartz (on Quartzite or Chert)
Silicon Dioxide (SiO2)
mineral
Gossan (Iron Hat) with Quartz and Chlorite
Limonite/Goethite-rich Gossan (FeO(OH)·nH2O) with inclusions of Quartz and Chlorite
Mineral/Metamorphic Substrate
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Basalt (Polished Pebble)
Basalt (Mafic volcanic rock)
igneous
Cobaltoan Calcite / Pink Dolomite (Possible)
Cobaltoan Calcite: (Ca,Co)CO3; Pink Dolomite (or Thulite): CaMg(CO3)2 or Mn-Dolomite / (Thulite: Mn2+3Al2(Si2O7)(SiO4)O(OH))
Mineral / Rock (depending on purity)
Sandstone (with Concretion)
Arenite / Quartzose Sandstone
sedimentary
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with FeO(OH) impurities)
sedimentary
Sandstone with Bedding Planes
Arenite (Sedimentary rock composed primarily of sand-sized minerals)
sedimentary
Chert (Nodular Chert)
Microcrystalline Silica (SiO2)
sedimentary
Massive Quartz with Host Rock
Silicon Dioxide (SiO2)
mineral
Chert (specifically Flint or Dark Chalcedony)
Silicon Dioxide (SiO2)
sedimentary
Quartz (likely a form of massive or vein quartz)
Quartz (SiO₂)
Mineral
Jasper Agate
Chalcedony (Silicon Dioxide - SiO2)
mineral
Quartz (Chert/Chalcedony Variety)
Silicon Dioxide (SiO2)
mineral
Quartzite
Quartzite (SiO2)
metamorphic
River Pebble (Gabbro or Basalt)
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
igneous
Diamond
Native Carbon (C)
mineral
Basalt
Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 with (Ca,Na)(Al,Si)4O8
igneous
Granite
Phaneritic Intrusive Igneous Rock (Granite)
igneous
Quartzite
Quartzite
Metamorphic rock
Basalt
Basalt (Mafic volcanic rock)
igneous
Chert (Flint)
Chert (predominantly SiO₂ - silicon dioxide)
sedimentary
Quartz (vein quartz)
SiO2 (Silicon Dioxide)
Mineral
Chert (Hagstone/Adder Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartzite with Chlorite/Epidote
Metamorphosed Quartzite (SiO2)
metamorphic
Blue Chalcedony (likely dyed)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Serpentine
Serpentinite (composed mainly of Group Minerals Antigorite, Chrysotile, and Lizardite; Mg3Si2O5(OH)4)
metamorphic
N/A - Image does not contain a rock or mineral
Anthropogenic textile material
Non-geological