Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
mineral
Category
Synthetic Polymer (Synthetic Material)
Browse synthetic polymer (synthetic material) specimens identified by the Rock Identifier community.
Epidote with Feldspar/Quartz (Unakite-like)
Epidotized Granite (Ca2(Al,Fe)3(SiO4)3(OH) + KAlSi3O8)
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Tufa
Calcareous Tufa (CaCO3)
sedimentary
Banded Chert (Ironstone/Jasper)
Cryptocrystalline Quartz (SiO2) with Iron Oxides
sedimentary
Granite Cobble
Granite (Phaneritic igneous rock composed of Quartz, Feldspar, and Mica)
igneous
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
mineral
Olivine (Peridot)
Magnesium Iron Silicate ((Mg, Fe)2SiO4)
mineral
Sandstone (Pebble)
Clastic sedimentary rock (SiO2 primary)
sedimentary
Quartzite Pebble
Quartzite (predominantly Silicon Dioxide - SiO2)
metamorphic
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
metamorphic
Diorite
Diorite
igneous
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Jasper River Pebble
Silicon Dioxide (SiO2)
sedimentary (microcrystalline quartz)
Pink Quartzite
Metamorphosed Quartz Arenite (SiO2)
metamorphic
Granite
Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica)
igneous
Limestone (specifically Fossiliferous or Crinoidal Limestone)
Calcium Carbonate (CaCO3) - Calcite Rock
sedimentary
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Jasper
Silicon Dioxide (SiO2)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
Igneous
White Marble
Recrystallized Calcite (CaCO3)
metamorphic
Jasper Conglomerate (Puddingstone)
Siliceous Conglomerate (Quartz and Jasper clasts in a fine-grained matrix)
sedimentary
Basalt
Mafic Volcanic Rock (composed of Plagioclase Feldspar and Pyroxene)
igneous
Unakite
Epidotized Granite (SiO2, KAlSi3O8, Ca2(Al, Fe)3(SiO4)3(OH))
metamorphic
Basalt
Basalt
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Jasper
Quartz (SiO2) with impurities
sedimentary
Slag Glass
Glassy Silicate Residue
industrial byproduct
Not a geological specimen
N/A (man-made object)
N/A
Granite
Granite (a broadly defined plutonic igneous rock, often more specifically classified as quartz monzonite or granodiorite based on precise mineral percentages)
igneous
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Sedimentary
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Metamorphic Rock
Iron Meteorite
Iron-nickel alloy (primarily kamacite and taenite)
Meteorite (extraterrestrial material)
Greywacke (River Pebble)
Greywacke sandstone with quartz veining
sedimentary
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
mineral
Tiffany Stone
Bertrandite (Be4Si2O7(OH)2) mixed with Fluorite (CaF2), Opal, and Chalcedony
mineral
Diabase (Greenstone)
Diabase (also known as Dolerite)
igneous
Lapis Lazuli
Lapis Lazuli (Mineral composition: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Calcite, and Pyrite)
metamorphic
Chrysoprase (Nickel-bearing Chalcedony)
Silicon Dioxide (SiO2) with traces of Hydrous Nickel Silicates
mineral
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
metamorphic