Granite
Granite (Phaneritic Igneous Rock)
Category
Browse sedimentary and igneous (mixed) specimens identified by the Rock Identifier community.
Granite
Granite (Phaneritic Igneous Rock)
Banded gneiss pebble
Gneiss, likely quartz–feldspar–mica gneiss
Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)
Quartz (SiO₂)
Vesicular basalt (likely weathered volcanic rock)
Basalt, commonly composed of plagioclase, pyroxene, and olivine
Basalt
Fine-grained mafic volcanic rock, chiefly plagioclase feldspar, pyroxene, and commonly olivine
Slag
Metallurgical Slag
Quartz
Quartz (SiO₂)
Greenstone
Metamorphosed Mafic Igneous Rock
Dark river pebble (likely basalt or andesite)
Fine-grained mafic/intermediate volcanic rock; commonly basalt (plagioclase ± pyroxene/olivine)
Basalt River Stone
Basalt (Aphanitic Mafic Igneous Rock)
Greenstone (Epidosite or Serpentinite)
Metabasalt / Epidote-Chlorite Schist
Dark basalt or fine-grained mafic rock
Basalt; primarily plagioclase feldspar, pyroxene, and commonly olivine or iron-titanium oxides
Quartz on Matrix
Silicon Dioxide (SiO2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Pyrite
Iron Sulfide (FeS2)
Yellow Chalcedony (Carnelian/Yellow Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Blue-dyed Quartz Druzy
Silicon Dioxide (SiO2) with artificial pigment
Fluorite
Fluorite (Calcium Fluoride, CaF2)
Amethyst
Amethyst (SiO2 - Silicon Dioxide with iron impurities)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Carnelian Agate
Carnelian (Silicon Dioxide: SiO2) with iron oxide impurities
Gneiss
Foliated Metamorphic Rock (Gneiss)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Sandstone (Red)
Arenite (primarily Quartz, SiO2, with Iron Oxide cement)
Milky quartz (quartz crystal)
Quartz, silicon dioxide (SiO₂)
Banded Chalcedony (Agate) in Basalt Matrix
Cryptocrystalline Quartz (SiO2) in Mafic Igneous Rock
Quartz-bearing rock or quartz-rich mineral specimen
Quartz, silicon dioxide (SiO₂); exact host rock is uncertain from the image
Hematite
Iron(III) oxide (Fe2O3)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Gneiss with Quartz Vein
Gneiss (containing SiO2 vein)
Hematite
Iron(III) oxide (Fe2O3)
Gneiss
Gneiss
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Quartz (possibly milky quartz)
Quartz (Silica; SiO₂)
Weathered mafic rock, likely basalt
Basalt; primarily plagioclase feldspar, clinopyroxene, and commonly olivine or magnetite
Fossil shell fragment
Indeterminate molluscan bioclast, likely aragonite or calcite
Rounded reddish-brown pebble
Likely ferruginous sandstone or iron-rich quartzite; exact identification requires a fresh surface and tests
Beryl (likely Pink/Morganite variety)
Beryllium aluminum silicate (Be3Al2Si6O18)
Garnet (likely Almandine or a blend)
Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.