Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Category
Mineralogical Specimen
Browse mineralogical specimen specimens identified by the Rock Identifier community.
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Biotite Schist with Garnet
Garnet-Biotite Schist
metamorphic
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Quartz / Quartzite
Silicon Dioxide (SiO2)
mineral
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
River Pebble (likely Quartzite or Basalt)
Quartzite (SiO2 as primary mineral)
metamorphic
Epidote with Quartz/Feldspar
Epidote (Ca2(Al, Fe)3(SiO4)3(OH)) with associated minerals in a host rock
Mineral/Metamorphic rock
Golden Healer Quartz
Silicon Dioxide (SiO2) with iron oxide inclusions
mineral
Quartz (Milky/Clear)
Silicon Dioxide (SiO2)
mineral
Chert (specifically Flint or Common Opal fragment)
Cryptocrystalline Silica (SiO2)
sedimentary
Man-made earbud charging case (Not a rock or mineral)
Acrylonitrile Butadiene Styrene (ABS) Plastic with electronic components
Synthetic/Man-made object
Eclogite
Eclogite (Pyrope garnet and Omphacite pyroxene)
metamorphic
Chert (or potentially Jasper/Chalcedony)
SiO2 (Silicon Dioxide)
sedimentary
Quartz Geode
Quartz (Silicon Dioxide, SiO2) in a Geode
sedimentary
Quartz (Iron-Stained)
Silicon Dioxide (SiO2)
mineral
Celestine (or Celestite)
Strontium sulfate (SrSO4)
mineral
Greenstone
Greenschist (composed of chlorite, actinolite, and epidote)
metamorphic
Gold Ore (in Quartz/Gossan matrix)
Native Gold (Au) in Limonite/Quartz matrix
mineral
Brecciated Limestone or Marble Pebble
Breccia / Calcite (CaCO3)
Sedimentary / Metamorphic
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 oxides)
sedimentary
Red Sandstone
Arenite with Hematite cementation
sedimentary
Labradorite
Labradorite (Ca,Na)(Al,Si)4O8
mineral
Quartzite (Iron-stained)
Quartzite (mostly SiO2 with Fe2O3 impurities)
metamorphic
Chert (Honey Chert / Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Gneiss (Metamorphic Pebble)
Gneissic Metamorphic Rock
metamorphic
Yellow Quartzite Pebble
Quartzite (SiO2)
metamorphic
Labradorite
Labradorite (Ca,Na)(Al,Si)4O8
mineral
Red Sandstone (Hematitic)
Clastic sedimentary rock (SiO2 with Fe2O3 inclusions)
sedimentary
Blue Sapphire (likely costume glass imitation)
Corundum (Al2O3) with iron/titanium impurities
mineral
Greywacke
Lithic wacke (variety of Sandstone)
sedimentary
Dyed Pumice
Vesicular Rhyolite (Artificial Coloration Addition)
igneous
Granite Cobble
Felsic intrusive igneous rock
igneous
Pyrite (on Shale/Matrix)
Iron Disulfide (FeS2)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartzite (Yellow/Iron-Stained)
Quartzite (SiO2 with Iron Oxide impurities)
metamorphic
Petrified Dinosaur Bone (Gembone)
Agatized Dinosaur Bone
sedimentary
Quartz (River Pebble)
Silicon Dioxide (SiO2)
mineral
Quartzite Pebble
Quartzite (SiO2)
metamorphic
Fulgurite
Fulgurite (Lechatelierite), amorphous SiO2
metamorphic
Lavender Agate / Chalcedony Sphere
Agate (Microcrystalline Quartz) - SiO2
mineral
Yellow Quartz (Citrine type/Tumbled Quartz)
Silicon Dioxide (SiO2)
mineral
Quartzite river stone
Quartzite (SiO2)
metamorphic