Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Category
Browse mixed (predominantly sedimentary and igneous) specimens identified by the Rock Identifier community.
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Basalt
Basalt (a mafic extrusive igneous rock)
Vesicular Basalt with Xenocrysts
Mafic Igneous Plutonic/Extrusive Complex
Granite Pebble
Granite (Phaneritic Acidic Igneous Rock)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Andesite
Andesite (Intermediate Extrusive Igneous Rock)
Diorite
Intrusive Igneous Diorite (intermediate composition)
Granite River Rock
Phaneritic Felsic Igneous Rock (Granite)
Granite
Phaneritic Acidic Igneous Rock (Granite)
Basalt (Vesicular)
Basalt (Extrusive Mafic Igneous Rock)
Crushed Rock (Basalt)
Basalt (Aphanitic Mafic Igneous Rock)
River Pebble (Basalt)
Basalt (Aphanitic Mafic Igneous Rock)
River Cobble (likely Basalt or Rhyolite)
Extrusive Igneous Rock (Mafic or Intermediate)
Basalt (River Stone)
Basalt (Aphanitic Mafic Igneous Rock)
Diorite
Diorite (Intermediate intrusive igneous rock)
Diorite (Polished Cobble)
Diorite (Intermediate intrusive igneous rock)
Granite
Granite (felsic intrusive igneous rock)
Basalt River Stone
Basalt (Aphanitic Mafic Igneous Rock)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Geode (Unopened)
Siliceous Septarian Concretion / Geode (SiO2)
Gastropod Fossil (Internal Mold)
Phylum Mollusca, Class Gastropoda (Steinkern)
Greisen
Greisen
Sandstone (likely Arkosic)
Clastic Sedimentary Rock (primarily SiO2 with Feldspar)
Milky Quartz (Water-worn pebble/nodule)
Quartz (Silicon Dioxide - SiO2)
Arsenopyrite in Quartz/Host Rock
Arsenopyrite (FeAsS)
Milky Quartz
Silicon Dioxide (SiO2)
Granite
Granite (a broadly defined plutonic igneous rock, often more specifically classified as quartz monzonite or granodiorite based on precise mineral percentages)
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
Peridot (Olivine)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Peacock Ore
Bornite (Cu5FeS4)
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
Biotite (Mica)
Biotite (K(Mg,Fe)3AlSi3O10(OH,F)2)
Red Garnet (Pyrope or Almandine)
Magnesium aluminum silicate (Mg3Al2(SiO4)3) or Iron aluminum silicate (Fe3Al2(SiO4)3)
Amethyst (Quartz)
Silicon Dioxide (SiO2) with iron impurities
Blue Quartz (Aventurine)
Silicon Dioxide (SiO2) with inclusions of crocidolite or dumortierite
Carnelian Agate
Silicon Dioxide (SiO2) with iron oxide inclusions
Sunstone
Oligoclase (Plagioclase Feldspar), (Na,Ca)(Si,Al)4O8