Opal
Hydrated amorphous form of silica (SiO2·nH2O)
Category
Browse mineral on sedimentary specimens identified by the Rock Identifier community.
Opal
Hydrated amorphous form of silica (SiO2·nH2O)
Sandstone (clastic)
Clastic Sedimentary Rock (primarily composed of SiO2)
Chert Pebble (Jasper/Quartz variety)
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Quartz (likely a form of massive or vein quartz)
Quartz (SiO₂)
Quartz (Druzy or Geode fragment)
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Shale
Argillaceous Rock
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (composed primarily of Quartz: SiO2)
Sandstone (Pebble/Conglomerate fragment)
Sandstone (clastic sedimentary rock)
Sandstone (Ferruginous)
Arenite (with iron oxide cement)
Quartz (Druzy)
Silicon Dioxide (SiO2)
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
Shale
Shale (comprised mostly of clay minerals and quartz)
Gneiss
Gneiss
Red Jasper
Quartz (Silicon Dioxide) with Hematite inclusions, SiO2
Pyrite with Limonite/Goethite Alteration (Pseudomorph)
Iron Sulfide (FeS2) transitioning to Hydrated Iron Oxides (FeO(OH)·nH2O)
Pyrite
Iron Disulfide (FeS2)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
Sandstone
Arenite
Milky Quartz
Silicon Dioxide (SiO2)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Megalodon Shark Tooth Fossil
Otodus megalodon
Blue Calcite
Calcium Carbonate (CaCO3)
Quartz / Clear Quartz
Silicon Dioxide (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Quartz
Silicon Dioxide (SiO2)
Pyrite in Shaly Matrix
Iron Sulfide (FeS2)
Banded Gneiss
Gneiss
Quartz (Milky or Smoky variant)
Silicon Dioxide (SiO2)
Yellow Calcite
Calcium Carbonate (CaCO3)
Carnelian Agate
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
Carnelian
Carnelian (SiO2 variant)
Pyrite
Iron Sulfide (FeS2)
Gold
Native Gold (Au)
Chalcedony (Tumbled)
Silicon Dioxide (SiO2)
Chalcedony (Common Opal variant or Chert/Flint)
Silicon Dioxide (SiO2)
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Milky Quartz (Ferruginous variety)
Silicon Dioxide (SiO2)