Porphyritic Basalt
Porphyritic Basalt (with Plagioclase phenocrysts)
Category
Browse mineral like byproduct (often mistaken for igneous rock or meteorite) specimens identified by the Rock Identifier community.
Porphyritic Basalt
Porphyritic Basalt (with Plagioclase phenocrysts)
Iolite (Cordierite)
Cordierite (Magnesium Aluminum Silicate), Mg2Al4Si5O18
Conglomerate with Quartz Inclusions
Conglomerate (clastic sedimentary rock) with internal Quartz (SiO2)
Nephrite Jade
Nephrite (a variety of the mineral actinolite within the amphibole group); Chemical Formula: Ca2(Mg,Fe)5Si8O22(OH)2
Greenschist (Greenstone River Pebble)
Greenschist (Chlorite Schist)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Greisen
Greisen
Labradorite
(Ca, Na)(Al, Si)4O8
Sandstone
Clastic sedimentary rock (primarily SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1-2, with varying amounts of Calcite, Pyrite, and Sodalite).
Citrine Quartz
SiO2 (Silicon Dioxide with Iron impurities)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Scoria (Lava Rock)
Mafic Vesicular Volcanic Rock
Pyrite
Iron Sulfide (FeS2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (primarily Quartz, SiO2, with Iron Oxide cementing agent)
Amazonite
K(AlSi3O8) - Microcline
Citrine
Silicon Dioxide (SiO2) with iron impurities
Basalt
Basalt (Mafic Extrusive)
Chert (Brecciated or Veined)
Silicon Dioxide (SiO2)
Shale
Fissile mudstone (primarily clay minerals and silt-sized quartz)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Red Jasper
Jasper (Silicate mineral - SiO2)
Chert (specifically Flint or Common Chert node)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Sandstone
Arenite (primarily SiO2)
Conglomerate
Conglomerate (clastic sedimentary rock type)
Basalt
Basalt (Mafic volcanic rock)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Pyrite
Iron Sulfide (FeS2)
Pink Granite
Granite (Phaneritic felsic intrusive igneous rock)
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities and natural radiation
Quartz
Quartz (Silicon Dioxide, SiO2)
Pink Granite
Felsic Intrusive Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)
Smoky Quartz
Silicon Dioxide (SiO2)
Granodiorite / Granite
Granodiorite (containing Quartz SiO2, Plagioclase Feldspar, and Biotite)
Botryoidal Agate
Chalcedony (Silicon Dioxide, SiO2)
Sandstone
Arenite (SiO2 based with various cements)
Shale
Shale (fine-grained clastic sedimentary rock)
Milk Quartz (with Iron staining)
Silicon Dioxide (SiO2)