Sandstone (Quartzose)
Arenite (Siliciclastic sedimentary rock)
sedimentary
Category
Mineral (Tectosilicate)
Browse mineral (tectosilicate) specimens identified by the Rock Identifier community.
Limonite (Iron Stone/Goethite)
Limonite (mixture of hydrated iron oxides, primarily Goethite: α-FeO(OH))
mineral
Banded Sandstone (River Pebble)
Clastic Sedimentary Rock (primarily Quartzite and Feldspar grains)
sedimentary
Sandstone
Arenite (primarily Quartz, SiO2)
sedimentary
Mica Schist
Schist (Crystalline metamorphic rock)
metamorphic
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
mineral
Diamond (Cut Specimen)
Carbon (C)
mineral
Biotite Schist
Biotite-rich Schist (K(Mg,Fe)3AlSi3O10(OH,F)2)
metamorphic
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
mineral
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
mineral
Garnet (Almandine/Pyrope)
Silicate Mineral (Group: X3Y2(SiO4)3 where X=Mg, Fe, Mn and Y=Al, Fe, Cr)
mineral
Mica Schist
Foliated Metamorphic Rock (rich in Muscovite or Biotite)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Granite
Plutonic felsic rock (Quartz, Feldspar, Mica)
igneous
Soapstone
Steatite (composed primarily of Talc, Mg3Si4O10(OH)2)
metamorphic
Green Aventurine (Quartzite)
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Granite
Phaneritic Igneous Rock (Granite)
igneous
Sandstone with Tafoni Weathering
Arenite (SiO2 based)
sedimentary
Ruby in Fuchsite
Corundum (Al2O3) in Chrome-Mica (KAl2(AlSi3O10)(OH)2)
metamorphic
Fulgurite
Fulgurite (Lechatelierite), amorphous SiO2
metamorphic
Smoky Quartz and Feldspar Pegmatite
Granitic Pegmatite (chiefly SiO2 and KAlSi3O8)
igneous
Basalt
Extrusive mafic igneous rock
igneous
Quartz Druzy on Agate (River Cobble)
Silicon Dioxide (SiO2)
Mineral / Sedimentary (often associated with volcanic hosts)
Yellow Chalcedony or River Jasper
Silicon Dioxide (SiO2)
sedimentary
Herkimer Diamond in Matrix
Quartz (SiO2) in Dolostone (CaMg(CO3)2)
sedimentary (host) / mineral (crystals)
Labradorite (Larvikite variety)
(Na,Ca)(Al,Si)4O8 (Plagioclase Feldspar)
igneous
Tiger Iron
Tiger Iron (composite of Tiger's Eye, Red Jasper, and Hematite)
metamorphic
Fuchsite on Quartzite
Muscovite (Chromium-bearing) K(Al,Cr)2(AlSi3O10)(OH)2
metamorphic
Fossil Rugose Coral (Horn Coral)
Order Rugosa (likely Grewingkia or Heliophyllum species); Calcium Carbonate (CaCO3)
sedimentary
Fuchsite on Quartz
Muscovite (KAl2(AlSi3O10)(OH)2) with Chromium impurities
metamorphic
Fluorite and Rose Quartz
Fluorite (CaF2), Rose Quartz (SiO2)
Mineral
Quartz with Mica inclusion
Silicon Dioxide (SiO2) with Muscovite/Biotite inclusions
igneous
Granite
Granite (Felsic intrusive igneous rock)
igneous
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
igneous
Mica Schist
Mica Schist (Schistose metamorphic rock rich in Muscovite/Biotite)
metamorphic
Magnetite / Iron Ore
Magnetite (Fe3O4)
mineral
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
mineral
Black Star Diopside
Diopside (CaMgSi2O6) with Magnetite inclusions
mineral
Rough Diamond
Diamond (pure Carbon, C)
mineral
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic