Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
Category
Browse organic mineraloid specimens identified by the Rock Identifier community.
Chert (often called Jasper or River Siltstone)
Microcrystalline Quartz (SiO2)
Honey Calcite
Calcium Carbonate (CaCO3)
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Tree Agate
Silicon Dioxide (SiO2) with Dendritic Inclusions
Green Moss Agate
Agate (Silicon Dioxide - SiO2 with inclusions of Manganese/Iron oxides)
Travertine
Tufa limestone (CaCO3)
Chalk
Calcium Carbonate (CaCO3)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Limestone (Fossiliferous)
Calcium Carbonate (CaCO3)
Angel Skin Coral
Corallium rubrum / Corallium spp. (Calcium Carbonate, CaCO3)
Dendritic Agate
Silicon Dioxide with inclusions (SiO2 + Mn/Fe)
Sand Tiger Shark Tooth
Carcharias taurus
Petrified Wood
Silicified Wood (SiO2)
Fossiliferous Limestone (Coral Fossil)
Scleractinian Coral in Calcium Carbonate (CaCO3)
Chert (Green River Chert)
Microcrystalline Quartz (SiO2)
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
Moss Agate
Chalcedony (SiO2) with dendritic inclusions of Manganese or Iron oxide
Limestone with Stylolites
Calcareous sedimentary rock (CaCO3)
Petrified Wood
Silicified wood (SiO2)
Fossilized Brachiopod
Brachiopoda (Phylum)
Chalcedony (Agate / Jasper Specimen)
Silicon Dioxide (SiO2)
Pitted Limestone
Calcium Carbonate (CaCO3)
Chert / Chalcedony
Silicon Dioxide (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Pyrite in Slate or Shale
Iron Sulfide (FeS2) in Argillaceous Matrix
Limestone (with Chert)
Calcium Carbonate (CaCO3) / Microcrystalline Quartz (SiO2)
Limestone
Calcium Carbonate (CaCO3)
Petrified Wood
Silicified Wood (SiO2)
Limestone
Calcium Carbonate (CaCO3 / Calcite)
Jasper
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified wood / Permineralized wood (SiO2)
Mammoth or Mastodon Tooth Fossil
Mammuthus / Mammut tooth
Jasper
Microcrystalline Quartz (SiO2)
Jasper
Silicon Dioxide (SiO2) microcrystalline quartz
Jasper
Microcrystalline Quartz (SiO2)
Jasper
Microcrystalline quartz (SiO2)
Fossilized Bone
Permineralized Vertebrate Bone
Shark Tooth Fossil
Vertebrate fossilized tooth (Chondrichthyes)
Shark Tooth Fossil
Vertebrate fossilized tooth
Chalcopyrite
CuFeS2
Chert (Iron-stained)
Microcrystalline Silica (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)