Amethyst
Amethyst (Silicon Dioxide, SiO2)
Category
Browse mineral (man made composite) specimens identified by the Rock Identifier community.
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Dyed Agate
Chalcedony (Silicon Dioxide, SiO2)
Amazonite
Potassium aluminum silicate (Microcline); KAlSi3O8
Amazonite (or Amazon Stone)
Potassium Feldspar (Microcline), K(AlSi3O8)
Clear Quartz
SiO2 (Silicon Dioxide)
Orthoceratid Fossil in Limestone
Orthoceras (extinct genus of Nautiloid Cephalopod)
Prehnite
Prehnite - Ca2Al(AlSi3O10)(OH)2
Thunderegg (specifically a Jasper/Agate-filled Geode nodule)
Silicon Dioxide (SiO2) within Rhyolitic Matrix
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Smoky Quartz
Silicon Dioxide (SiO2)
Amazonite
Microcline (Amazonstone), K(AlSi3O8)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Agate Geode
Chalcedony (cryptocrystalline SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Sandstone with Liesegang Rings
Arenite with Iron Oxide Concretions
Prehnite with Epidote inclusions
Prehnite: Ca2Al(AlSi3O10)(OH)2; Epidote: Ca2(Al,Fe)3(SiO4)3(OH)
Greenstone
Chlorite schist or metabasalt depending on specific composition
Pyrite
Iron Sulfide (FeS2)
Chalcedony
Chalcedony (SiO2)
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2 (Calcium magnesium iron silicate)
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Gneiss (Pebble)
Gneiss
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Granite
Granite (Felsic intrusive igneous rock)
Granite
Granite (Phaneritic Igneous Rock)
Granite
Phaneritic Felsic Igneous Rock
Granite
Granite (Felsic Plutonic Rock)
Schist
Mica Schist
Jasper or Agate with Chlorite Inclusions
Silicon Dioxide (SiO2) with Chlorite group minerals
Red Ochre (Hematite-rich Clay)
Limonitic/Hematitic Claystone (Fe2O3 with clay minerals)
Banded Rock (likely Quartz-rich)
Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals
White Quartz Pebble
Quartz (Silicon Dioxide - SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Yellow Citrine Quartz
Silicon Dioxide (SiO₂)
Native Gold (in Jewelry)
Gold (Au)
Granite
Granite (Felsic Intrusive Igneous Rock)
Green Aventurine
Silicon dioxide (SiO2) with Fuchsite inclusions
Amygdaloidal Rhyolite
Amygdaloidal felsic extrusive rock
Quartz Vein on Matrix
Silicon Dioxide (SiO2)
Amygdaloidal Rhyolite (often called Lake Superior Agate relative)
Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)
Pegmatite (likely Granitic Pegmatite)
Pegmatite (a coarse-grained igneous rock, often with granitic composition)