Bauxite
Al2O3·2H2O (principally composed of gibbsite, boehmite, and diaspore)
Category
Browse sedimentary (synthetic) specimens identified by the Rock Identifier community.
Bauxite
Al2O3·2H2O (principally composed of gibbsite, boehmite, and diaspore)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (with potentially metamorphic or basaltic bands)
Arenite / Lithic Wacke
Limestone (Grey and White specimens)
Calcium Carbonate (CaCO3)
Sandstone (specifically Flagstone)
Arenite (primarily composed of SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
Sandstone with Liesegang Rings
Arenite with Iron Oxide Concretions
Sandstone with Foliose Lichen
Arenite (Rock matrix) with Xanthoparmelia or Flavoparmelia (Lichen genus)
Concretion
Various mineral compositions, typically carbonate or iron oxide cemented sediment
Quartz (likely milky/rose quartz variety)
Quartz (SiO2 - Silicon Dioxide)
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement (primarily SiO2 with Fe2O3/FeOOH)
Limestone with Algal/Lichen Colonization
Calcium Carbonate (CaCO3)
Sandstone Pebble
Arenite (primarily SiO2)
Banded Chert or Chert with Quartz Veins
Chert (SiO2)
Pyrite
Pyrite (FeS₂)
Green Kyanite
Kyanite (Al2SiO5)
Chalcedony (specifically Agate or Carnelian)
Silicon Dioxide (SiO2)
Mookaite Jasper
SiO2
Yellow Chalcedony (Agate)
Silicon Dioxide (SiO2)
Chert (Jasper)
Silicon Dioxide (SiO2)
Siderite Concretion in Shale
Iron carbonate (FeCO3) in Mudstone/Shale matrix
Chert Nodules / Flint
Crystalline Silica (SiO2)
Chert (Jasper)
Cryptocrystalline Silicon Dioxide (SiO2)
Blue Aragonite
Aragonite (Calcium Carbonate, CaCO3)
Common Opal
Hydrated Silica (SiO2·nH2O)
Caribbean Calcite
Calcite and Aragonite (CaCO3)
Chert / Jasper
Cryptocrystalline Quartz (SiO2)
Quartz or possibly Jasper/Chert. Looks like a tumbled or water-worn stone.
SiO2 (Silicon Dioxide)
Geode (Unopened)
Chalcedony/Quartz Geode (SiO2)
Sulfur on matrix
Native Sulfur (S8)
Leopard Skin Jasper
Silicon Dioxide (SiO2) with impurities
Banded Agate (Silk Agate or Maligano Jasper variant)
Silicon Dioxide (SiO2)
Carnelian (Agate)
Silicon Dioxide (SiO2)
Brown Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartz
Silicon Dioxide (SiO2)
Chalcedony (Botryoidal)
Silicon Dioxide (SiO2)
Opal
Hydrated Silica (SiO2·nH2O)
River Rock (likely Basalt or Greywacke)
Basalt or Lithic Sandstone
Agate (Chert/Chalcedony)
Cryptocrystalline Quartz (SiO2)
Limonite/Ironstone
Limonite (FeO(OH)·nH2O)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Magnetite / Hematite rich ore
Magnetite (Fe3O4) or Hematite (Fe2O3)