Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Category
Browse mineral, often found as detrital grains in sedimentary rocks specimens identified by the Rock Identifier community.
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (composed mainly of SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartzite
Quartzite (SiO2)
Pyrite
Iron Disulfide (FeS2)
Hematite (Iron Ore)
Hematite (Fe2O3)
Granite Cobble / Rounded Granite River Rock
Granite
Jasper
Silicon dioxide (SiO2)
Magnetite (Lodestone variety)
Magnetite (Fe3O4)
Diorite (Salt and Pepper Rock)
Diorite
Ferruginous Sandstone Pebble
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3/FeO(OH) staining)
Zebra Jasper
Silicon dioxide (SiO2) with various impurities
Painted River Rock
Anthropogenic-modified Siliciclastic Sedimentary Rock
Yellow Chert or Jasper
Microcrystalline Quartz (SiO2)
Chert (and Petrified Wood)
Silicon Dioxide (SiO2)
Red Jasper (Chert)
Silicon Dioxide (SiO2)
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2 (Silicon Dioxide)
Sapphirine in Magnesian Schist
Sapphirine: (Mg,Al)8(Al,Si)6O20
Granite Pebble (Weathered)
Phaneritic Felsic Igneous Rock
Jasper (specifically Oolitic or Brecciated Jasper)
Silicon Dioxide (SiO₂)
Limestone (with potential fossil inclusions)
Calcium Carbonate (CaCO3)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Quartzite and Jasper Pebbles
Quartzite (re-crystallized Quartz) and Cryptocrystalline Quartz (SiO2)
Agate with Quartz Druzy
Silicon Dioxide (SiO2) - Microcrystalline and Macrocrystalline varieties
Shale
Shale (comprised mostly of clay minerals and quartz)
Diorite
Diorite
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3)
Sodalite
Sodium aluminum silicate chloride (Na8(Al6Si6O24)Cl2)
Hag Stone
Calcareous sedimentary rock (often Chert, Flint, or Limestone)
Schist
Mica Schist
Quartz (Chert/Chunky Chalcedony)
Silicon Dioxide (SiO2)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Bornite
Bornite (Cu5FeS4)
Blue Lace Agate
Agate (Variety of Chalcedony, SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron Oxide inclusions
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Chert (and Chert Geode)
Silicon Dioxide (SiO2)
Chert (specifically Red Chert / Jasper nodule)
Silicon dioxide (SiO2)
Basalt with Weathered Surface
Basalt
Granite featuring Quartz Vein
Granite with hydrothermal silica (SiO2) intrusion
Carnelian (Orange Chalcedony)
Silicon dioxide (SiO2)