Quartz Geode Fragment
Silicon Dioxide (SiO2)
Category
Browse mineral on sedimentary specimens identified by the Rock Identifier community.
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2) within a geode
Quartz Geode
Silicon Dioxide (SiO2)
Small pale mineral fragment, likely quartz or calcite
Tentatively quartz (SiO₂) or calcite (CaCO₃); image resolution prevents confident identification
Gneiss
Gneiss
Tumbled Mixed Gemstones and Rocks
Various mineral species including quartz (SiO2) and silicate minerals
Sandstone
Arenite
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
Caribbean Calcite
Calcium Carbonate with Argonite (CaCO3)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with Fe2O3/FeOOH cement)
Gold Mineral
Native Gold (Au)
Shale
Shale (clastic sedimentary rock)
Rhodochrosite
Manganese carbonate (MnCO3)
Blue Howlite (Dyed)
Dyed Howlite (Calcium Borosilicate Hydroxide, Ca2B5SiO9(OH)5)
Blue Howlite (Dyed)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
Quartzite Sandstone / Quartz Sandstone
Quartz Sandstone (SiO2 with minor mineral impurities)
Likely banded gneiss
Gneiss, a foliated metamorphic rock composed chiefly of quartz, feldspar, and mica
Limonite (Ironstone)
FeO(OH)·nH2O
Limonite / Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O)
Sedimentary Outcrop (Sandstone/Shale)
Sedimentary bedrock formation (variable composition)
Shale
Argillite / Shale
Sandstone (Iron-stained)
Arenite (primarily SiO2 with Fe2O3 staining)
Light-colored limestone
Calcitic limestone; primarily calcium carbonate (CaCO₃), mineral calcite
Aragonite Star Cluster (Cross-section)
Aragonite (Calcium Carbonate, CaCO3)
Quartz
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Halite (Rock Salt)
Halite (Sodium Chloride, NaCl)
Orange Calcite (Cleavage Rhomb)
Calcite (Calcium Carbonate, CaCO3)
Limonite/Ironstone
Limonite (FeO(OH)·nH2O)
River Stone (Sandstone or Siltstone)
Sedimentary Rock (Clastic)
Banded Sandstone
Clastic Sedimentary Sandstone
Sandstone
Clastic Sedimentary Rock
Sandstone
Clastic Sedimentary Rock
Sandstone
Clastic Sedimentary Rock
Pyrite with Quartz
Iron Sulfide (FeS2) with Silicon Dioxide (SiO2)
Sandstone (with minor weathering/pitting)
Clastic Sedimentary Rock (composed mostly of SiO2)
Agate Geode
Silicon Dioxide (SiO2) - Chalcedony variety
Galena
Lead Sulfide (PbS)
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Pyrite
Iron Sulfide (FeS2)
Sandstone (likely Arkose or Lithic)
Clastic sedimentary rock (SiO2 + impurities)
Sandstone
Clastic Sedimentary Rock