Sandstone
Clastic sedimentary rock (primarily SiO2)
Category
Browse mineral or sedimentary (if chert) specimens identified by the Rock Identifier community.
Sandstone
Clastic sedimentary rock (primarily SiO2)
Shale
Fissile Siliciclastic Sedimentary Rock
Dinosaur Fossil (Tyrannosaurus rex skull replica/specimen)
Tyrannosaurus rex (fossilized in permineralized sedimentary matrix)
Red Jasper (Tumbled)
Silicon Dioxide (SiO2) with iron oxide inclusions
Blue Chalcedony
Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)
Blue Chalcedony
Chalcedony (Silicon Dioxide, SiO2)
Quartz Geode or Druzy Quartz in Host Rock
Silicon Dioxide (SiO2)
Red Jasper
Silicon Dioxide with Iron inclusions (SiO2 + Fe2O3)
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
Geode with Quartz and Chalcedony
Silicon Dioxide (SiO2)
Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
Sandstone
Arenite (primarily SiO2)
Quartz (Small Fragment)
Silicon Dioxide (SiO2)
Sandstone Beach Pebble
Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)
Halite
Halite (NaCl)
Ironstone Concretion
Siderite or Hematite Concretion (FeCO3 or Fe2O3)
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Bivalve Fossil (Internal Mold/Steinkern)
Class Bivalvia (Fossilized Mold)
Concretion
Sedimentary Concretion (e.g., Siderite or Ironstone)
Seashell Fragment (Aragonite/Calcite)
Calcium Carbonate (CaCO3) - Shell fragment
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
Hematite Nodular Iron Ore
Hematite (Fe2O3)
Quartz
Silicon Dioxide (SiO2)
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Satin Spar (Selenite)
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
Hematite
Iron(III) oxide (Fe2O3)
Quartz Geode
Silicon Dioxide (SiO2) within a geode
Pyrite (Fool's Gold) in Matrix
Iron Sulfide (FeS2)
Quartz
Silicon Dioxide (SiO2)
Limonite
Limonite (Hydrated iron(III) oxide-hydroxide) FeO(OH)·nH2O
Hematite
Iron(III) oxide (Fe2O3)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Chalcedony (Grey/White Agate)
Silicon Dioxide (SiO₂)
Quartz Geode
Silicon Dioxide (SiO2)
Chalcedony (Agate/Quartz pebble)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Blue Calcite
Calcium Carbonate (CaCO3)
Pyrite (on Quartz matrix)
Iron Disulfide (FeS2)
Gold Nugget
Native Gold (Au)