Unidentifiable Specimen
Undetermined
Category
Browse sedimentary (secondary formation) specimens identified by the Rock Identifier community.
Unidentifiable Specimen
Undetermined
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Banded River Cobble with Mafic Dike
Hydrothermally altered Graywacke or Sandstone with Mafic Intrusion
Mica-rich Sandstone or Micaceous Schist Weathering
Micaceous Schist (Muscovite-Quartz composition)
Limonite (Iron Ore)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
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]
Yellow Calcite
Calcium Carbonate (CaCO3)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminium phosphate)
Quartz in Limonite-rich Matrix
Silicon Dioxide (SiO2) with Goethite/Limonite FeO(OH)·nH2O
Limonite (with Pyrite)
Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O
Ferruginous Quartz
Quartz (Silicon Dioxide, SiO2) with iron oxide inclusions
Jasper
Jasper (Cryptocrystalline Quartz, SiO2)
Chert (often called Flint when dark or found in chalk)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Jasper
Silicon dioxide (SiO2) with iron oxide inclusions
Red Jasper
Silicon dioxide (microcrystalline quartz with iron oxide inclusions), SiO2
Red Jasper (nodule)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Honey Calcite Geode Segment
Calcite (Calcium Carbonate, CaCO3)
Limonite (with Goethite/Ironstone)
FeO(OH)·nH2O (Hydrated Iron Oxide)
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O
Rhodochrosite
Manganese Carbonate (MnCO3)
Chalcedony
Silicon dioxide (SiO2) - Microcrystalline quartz
Turquoise
Hydrous phosphate of copper and aluminium - CuAl6(PO4)4(OH)8·4H2O
Fossilized Fish Skeleton in Matrix
Vertebrata (Class: Actinopterygii), typically found in limestone or shale matrices
Limestone
Calcium Carbonate (CaCO3)
Quartz Geode in Chert/Limestone Matrix
Silicon Dioxide (SiO2) within Sedimentary Host Rock
Agate Geode
Silicon Dioxide (SiO2) - variety Chalcedony/Quartz
Limonite and Goethite encrusted Chert/Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O) with cryptocrystalline Silica (SiO2)
Rough Agate/Chert Nodules
Cryptocrystalline Quartz (SiO2)
Tufa
Calcareous Tufa (CaCO3)
Chalcedony (specifically Agate or Common Opal variety)
Cryptocrystalline Silica (SiO2)
Chalcedony (Botryoidal/Drusy Quartz)
Silicon Dioxide (SiO₂)
Druzy Quartz on Matrix (likely Limestone or Sandstone)
Silicon Dioxide (SiO2) with various trace impurities
Shiva Lingam
Cryptocrystalline Quartz (Jasproid/Sandstone) with Iron Oxide (Fe2O3)
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Spondylus Oyster Calcification / Fossilized Oyster
Spondylus (Thorny Oyster) / Calcium Carbonate (CaCO3)
Red Jasper
Jasper (Silicon Dioxide, SiO2)