Sandstone (Ferruginous)
Arenite (with high iron oxide content)
sedimentary
Category
Mineral, Often A Rock Given Its Aggregate Nature
Browse mineral, often a rock given its aggregate nature specimens identified by the Rock Identifier community.
River Stone (Chert/Siltstone)
Cryptocrystalline Quartz (SiO2) with trace impurities
sedimentary
Cullet Glass (Strawberry Glass)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Mineraloid (Synthetic/Man-made)
Basalt (Weathered Pebble)
Extrusive mafic igneous rock; minerals primarily Plagioclase feldspar and Pyroxene
igneous
Brecciated Jasper
Silicon Dioxide (SiO2) with Hematite and Quartz inclusions
sedimentary
Basalt
Mafic Igneous Rock
igneous
Breccia
Breccia
sedimentary
Yellow Quartzite
Quartzite (SiO2 with iron oxide inclusions)
metamorphic
Sandstone
Clastic Sedimentary Rock (composed primarily of Quartz, SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
Mineral/Sedimentary
Greenstone
Greenschist / Greenstone (Chlorite-Epidote facies)
metamorphic
Chert (Hagstone/Adder Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
African Turquoise (Jasper)
Polychrome African Jasper (often marketed as 'African Turquoise' due to its color, but it is not true turquoise)
Rock
Magnetite
Magnetite (Fe3O4)
Mineral
Granite
Plutonic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
igneous
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Unakite
Unakitized granodiorite / Quartz-Epidote-Feldspar rock
metamorphic
Oolitic Chert
Silicon Dioxide (SiO2) with Oolitic texture
sedimentary
Chert (Tan/Yellow variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Amethyst
Silicon Dioxide (SiO2) with traces of Iron and Manganese
mineral
Quartz Vein Outcrop
Silicon Dioxide (SiO2)
mineral
Clear Quartz (Carved Dragon)
Quartz (Silicon Dioxide, SiO2)
mineral
Basalt Beach Pebble
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
mineral
Quartz (Chert/Chalcedony Variety)
Silicon Dioxide (SiO2)
mineral
Amphibolite (specifically Hornblende Schist/Gneiss)
Amphibole-rich Metamorphic Rock
metamorphic
Basalt
Extrusive mafic igneous rock
igneous
Quartz with Iron Staining
Silicon Dioxide (SiO2) with FeOx inclusions
mineral
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Rose Quartz
Quartz (Silicon Dioxide - SiO2) with trace amounts of titanium, iron, or manganese
mineral
Gneiss with Quartz Veining
Gneiss (High-grade regional metamorphic rock)
metamorphic
Sandstone with Ironstone Banding
Clastic Sandstone (composed of Quartz with Hematite/Limonite bonding)
sedimentary
Quartzite Pebble (with Iron Staining)
Quartzite (SiO2)
metamorphic
Pyrite on Quartz matrix
Iron Disulfide (FeS2) on Silicon Dioxide (SiO2)
mineral
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
mineral
Muscovite Mica
Muscovite - KAl2(AlSi3O10)(OH)2
mineral
Banded Iron Formation (BIF)
Banded Iron Formation
Sedimentary
Unakite
Epidote-Feldspar rock
Metamorphic Rock
Sandstone
Arenite (often composed of Quartz, SiO2)
sedimentary
Basalt River Stone
Aphanitic Mafic Igneous Rock
igneous