Basalt
Basalt (primarily Plagioclase feldspar and Pyroxene)
igneous
Category
Metamorphic (Likely Gneiss Or Schist Based On Texture)
Browse metamorphic (likely gneiss or schist based on texture) specimens identified by the Rock Identifier community.
Granodiorite
Granodiorite (containing Quartz, Plagioclase Feldspar, Biotite, and Hornblende)
igneous
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
mineral
Obsidian
Obsidian (volcanic glass)
igneous
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Quartzite
Metamorphic Quartz Sandstone (SiO2)
metamorphic
Graphite
Graphite (Native Carbon), Formula: C
Metamorphic
Blue Onyx (Dyed Agate)
Cryptocrystalline Quartz (SiO2) with artificial pigment
mineral
Basalt with Quartz/Calcite Inclusions
Mafic Volcanic Rock (Fe-Mg silicate rich)
igneous
Serpentine
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Granitoid Pebble (Graphic Granite/Pegmatite)
Pegmatitic Granite with Quartz and Orthoclase
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Milky Quartz with Mineral Inclusions
Quartz (Silicon Dioxide - SiO2)
mineral
Pink Granite
Phaneritic Felsic Igneous Plutonic Rock
igneous
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions (SiO2)
igneous
Fossiliferous Sandstone (with Brachiopod or Bivalve mold)
Clastic Sedimentary Rock with Macrofossil Mold
sedimentary
Chert (Nodule/Pebble)
Chert (Silicon Dioxide, SiO2)
sedimentary
Siltstone or Mudstone
Argillaceous sedimentary rock
sedimentary
Porphyritic Basalt
Porphyritic Basalt (with Plagioclase phenocrysts)
igneous
Jasper
Silicon dioxide (SiO2) with iron impurities
sedimentary
Slate with Iron Staining
Low-grade Metamorphic Mudstone (Slate)
metamorphic
Sandstone (likely Quartzose)
Arenite (SiO2 principal mineral)
sedimentary
Quartz (specifically Milky/White Quartz)
Silicon Dioxide (SiO2)
mineral
Basalt
Basalt (composition of plagioclase feldspar and pyroxene)
Igneous
Green Aventurine (likely)
Silicon dioxide (SiO2) with fuchsitemica inclusions
Mineral (specifically a variety of Quartz)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
mineral
Basalt
Basalt (Extrusive Mafic Igneous Rock)
igneous
Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3 iron oxide staining)
sedimentary
Asphalt (Aggregate)
Bituminous macadam / Concrete Aggregate
sedimentary
Vesicular Basalt or Scoria
Basalt (extrusive volcanic rock)
igneous
Blue Chalcedony
Chalcedony (Silicon Dioxide, SiO2)
mineral
Seraphinite
Clinochlore (a variety of the chlorite group)
mineral
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral, often found as detrital grains in sedimentary rocks
Tektite (likely Indochinite)
Tektite (high-silica impact glass)
igneous
Yellow Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Granite
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
igneous
Petrified Wood
Silicified Wood / Chalcedony (SiO2)
mineral
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Rainbow Moonstone with Black Tourmaline
White Labradorite with Schorl (Na,Ca)(Al,Si)4O8
mineral
Greenschist (Greenstone)
Greenschist (Metamorphic rock containing chlorite, actinolite, and epidote)
metamorphic
Amazonite (or Amazon Stone)
Potassium Feldspar (Microcline), K(AlSi3O8)
mineral