Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Category
Mineral Like Byproduct (Often Mistaken For Igneous Rock Or Meteorite)
Browse mineral like byproduct (often mistaken for igneous rock or meteorite) specimens identified by the Rock Identifier community.
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Basalt
Basalt (Mafic Extrusive)
igneous
Granite Cobble (River Stone)
Felsic intrusive igneous rock (composition: Quartz, Feldspar, Mica)
igneous
River Cobble (likely Basalt or Greenstone)
Mafic Igneous Rock (with possible chloritic alteration)
igneous
Geode (Quartz / Chalcedony Geode)
SiO2 (Silicon Dioxide)
sedimentary
Sandstone (Pebble)
Arenite (SiO2 based)
sedimentary
Basalt
Extrusive Igneous Rock
igneous
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
mineral
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Pumice
Pumice (Amorphous volcanic glass)
igneous
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Shale
Shale (Fine-grained clastic sedimentary rock)
sedimentary
Granodiorite
Granodiorite
igneous
Sandstone
Sedimentary Clastic Rock (Quartz-rich)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
sedimentary
Sedimentary Pebble
Sedimentary Rock Fragment
sedimentary
Granite Gneiss
Gneiss (derived from granitic protolith)
metamorphic
Druzy Quartz on Sandstone
Silicon Dioxide (SiO2) with Quartz Crystals on Clastic Sedimentary Rock
sedimentary
Diorite (Salt and Pepper Rock)
Diorite
igneous
Diorite (Dalmatian Stone variant)
Phaneritic Intermediate Plutonic Rock (Diorite)
igneous
Sandstone
Arenite (SiO2 with various cementing minerals)
sedimentary
Basalt
Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Igneous
Granite Cobble
Phaneritic Plutonic Felsic Rock
igneous
Quartz
Silicon Dioxide (SiO2)
mineral
Obsidian
Volcanic Glass (SiO2)
igneous
Quartz Druzy (on Matrix)
Silicon Dioxide (SiO2)
mineral
Citrine
SiO2 (Silicon Dioxide)
mineral
Quartz Vein in Siltstone
Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix
metamorphic
Smoky Quartz
Smoky Quartz (SiO2: Silicon Dioxide)
mineral
Blue Dumortierite Quartz
Dumortierite in Quartz (AlAl6BSi3O18)
metamorphic
Gneiss
Gneissic Metamorphic Rock
metamorphic
Purple Lava Rock / Vesicular Basalt
Vesicular Basalt (Mafic Extrusive Igneous Rock)
igneous
Variscite (or potentially a turquoise/variscite matrix cabochon, or an impression jasper)
AlPO4·2H2O (Variscite) or related phosphate/silicate material depending on exact composition
Mineral
Scoria (Lava Rock)
Scoria (vesicular basaltic rock)
igneous
Schist
Schist (various mineralogical compositions including mica, chlorite, talc, etc.)
Metamorphic
Hematite (likely Botryoidal or Specularite variant)
Iron(III) oxide (Fe2O3)
mineral
Greenstone (Greenschist)
Greenschist facies rock (containing chlorite, actinolite, and epidote)
metamorphic
Pumice
Pumice (volcanic glass with vesicular texture)
igneous
Pumice (Vesicular Rhyolite/Andesite)
Pumice (a highly vesicular volcanic glass/extrusive igneous rock)
igneous
Shale
Sedimentary rock composed of clay minerals and quartz
sedimentary