Basalt
Extrusive Igneous Rock
Category
Browse mineral like (anthropogenic) specimens identified by the Rock Identifier community.
Basalt
Extrusive Igneous Rock
Inukshuk Rock Sculpture (composed of Granite, Slate, and Amethyst)
Silicon Dioxide (Amethyst portion, SiO2) with mixed silicate rock assemblage
Spinel
Magnesium aluminum oxide (MgAl2O4)
Sandstone
Clastic sedimentary rock (Quartz arenite / Arkose)
Pegmatite with Mica
Granitic Pegmatite (containing Muscovite and Biotite)
Petrified Wood
Silicified Wood (primarily SiO2)
Quartz with Schist Inclusion
Crystalline Silicon Dioxide (SiO2) with Muscovite/Biotite Schist
Garden Quartz (Lodolite)
Quartz with inclusions (SiO2 + various inclusions such as Chlorite, Hematite, or Feldspar)
Granite
Phaneritic Felsic Igneous Rock
Porphyritic Rhyolite
Porphyritic Rhyolite (SiO2)
Schist
Mica Schist
Quartz Geode (Druzy Quartz)
Silicon Dioxide (SiO2)
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
Mica Schist
Mica Schist (predominantly Muscovite or Biotite sheet silicates)
Quartz with Epidote inclusions
Silicon Dioxide (SiO2) with Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Orange Calcite
Calcium Carbonate (CaCO3)
Blue Apatite
Fluorapatite / Apatite Group Ca5(PO4)3(F,Cl,OH)
Greenstone
Protolith of basalt/gabbro (chlorite-epidote metamorphic facies)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Tree Agate
Dendritic Chalcedony (SiO2)
Gravel and Pebbles
Unconsolidated rock fragments (clastic sediment)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Muscovite (Mica)
Muscovite - KAl2(AlSi3O10)(OH)2
Black Tourmaline
Schorl (Sodium Iron Aluminum Borosilicate Hydroxide)
Garnet (specifically Almandine or Pyrope)
Almandine: Fe3Al2(SiO4)3 or Pyrope: Mg3Al2(SiO4)3
Blue Sapphire
Corundum (Al2O3 with trace Titanium and Iron)
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Quartz
Silicon Dioxide (SiO2)
Milky Quartz with Iron Inclusions
Silicon Dioxide (SiO2)
Amethyst (Raw Quartz)
Silicon Dioxide (SiO2) with iron impurities
Quartz Geode fragment
Crystalline Silicon Dioxide (SiO2)
Diorite
Plutonic Igneous Rock (Intermediate Composition)
Blue Apatite
Fluorapatite - Ca5(PO4)3F
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
Garnet
Garnet group (X3Y2(SiO4)3)
Blue Sapphire
Corundum (Al2O3) with iron and titanium impurities
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Magnetite
Iron(II,III) oxide (Fe3O4)
Potassium Feldspar
Orthoclase (KAlSi3O8)
Plagioclase Feldspar
Plagioclase Feldspar Series (NaAlSi3O8 - CaAl2Si2O8)