Granite
Plutonic felsic igneous rock
Category
Browse mineral like (anthropogenic) specimens identified by the Rock Identifier community.
Granite
Plutonic felsic igneous rock
Amethyst or Smoky Quartz Geode Slice
Crystalline Silicon Dioxide (SiO2) with iron impurities
Green Schist
Greenschist (composed of Chlorite, Actinolite, and Epidote)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Obsidian
Amorphous volcanic glass (SiO2)
Ironstone Concretion
Siderite or Hematite Concretion
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Vanadinite
Vanadinite (Pb5(VO4)3Cl)
Botryoidal Goethite
Goethite (α-Fe3+O(OH))
Montana Moss Agate
Chalcedony (SiO2) with Manganese/Iron oxide inclusions
Yellow Jasper
Silicon Dioxide (SiO2) with hydrated iron oxide impurities
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Peach Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
Limonite (Iron Ore)
FeO(OH)·nH2O
Schist with Biotite and Quartz
Biotite-Quartz Schist (Fe,Mg,Al silicate mix)
Turquoise with Pyrite
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O] with Iron Pyrite (FeS2)
Quartz with Limonite Staining
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)
Graphic Granite
Graphic Granite (a runic intergrowth of Quartz and Feldspar)
Sandstone
Arenite (SiO2 based with various mineral cements)
Sandstone
Arenite (SiO2 based)
Obsidian
Obsidian (Volcanic Glass, primarily SiO2)
Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles
Mixed gemstones (primarily Silicon Dioxide - SiO2)
Silicon Carbide (Carborundum)
Moissanite (SiC), though mostly synthetic
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Limonite (Iron Ore)
Limonite (unstructured hydrated iron(III) oxide-hydroxides, often FeO(OH)·nH2O)
Gneiss
Gneiss (High-grade regional metamorphic rock)
Geode (Unopened)
Crystalline Quartz or Chalcedony filled Geode (SiO2)
Snowflake Obsidian
Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions
Porphyritic Rhyolite
Porphyritic Rhyolite (SiO2)
Quartz with Schist Inclusion
Crystalline Silicon Dioxide (SiO2) with Muscovite/Biotite Schist
Granite
Phaneritic Felsic Igneous Rock
Garden Quartz (Lodolite)
Quartz with inclusions (SiO2 + various inclusions such as Chlorite, Hematite, or Feldspar)
Schist
Mica Schist
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Prase or Green Quartz
Silicon Dioxide (SiO2 with actinolite or chlorite inclusions)
Concrete Fragment
Hardened Portland Cement Composite
Quartz Geode
Silicon Dioxide (SiO2)
Sandstone
Arenite
Fossil / Permineralized Bone
Tyrannosaurus rex fossil (Hydroxylapatite replaced by various minerals)