Orthoceras Fossil Limestone
Orthoceras (extinct genus of cephalopod); Limestone matrix (CaCO3)
Category
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
Orthoceras Fossil Limestone
Orthoceras (extinct genus of cephalopod); Limestone matrix (CaCO3)
Red Chert (Jasper)
Silicon Dioxide (SiO2) with iron oxide inclusions
Chalcedony (Common Agate)
Silicon Dioxide (SiO2)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Fancy Jasper
Jasper (Cryptocrystalline Quartz, SiO2)
Oyster shell fragment
Ostreidae shell; primarily calcite (CaCO₃)
Sandstone (Quartz Arenite)
Sandstone (SiO2 with possible mineral cements)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Polished pink chalcedony (likely pink agate/geode)
Microcrystalline quartz, SiO₂; chalcedony with iron-bearing inclusions and possible druzy quartz
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert / Flint
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Jasper variety)
Silicon Dioxide (SiO2) with iron oxide impurities
Petrified Wood
Silicified Wood (primarily SiO2)
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Turquoise bead bracelet
Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O
Dyed Magnesite (often sold as Red Turquoise or Howlite)
Magnesium Carbonate (MgCO3)
Jasper
Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)
Chert (often called Flint when found in chalk)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Silicon Dioxide (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Kambaba Jasper
Stromatolite (Fossilized Algae within Microcrystalline Quartz)
Fossil Coral
Hexagonaria (or Rugose/Tabulate coral fossilized in calcium carbonate)
Sandstone with attached barnacles
Quartz sandstone (Silicon Dioxide - SiO2 matrix)
Fossiliferous Sandstone / Quartzite Pebble
Sedimentary rock with skeletal fragments (e.g., Paleozoic crinoid/brachiopod fossils)
Sandstone Cobble
Arenite (primarily SiO2)
Sandstone Pebble (River Rock)
Arenite (primarily SiO2)
Conglomerate
Conglomerate (clastic sedimentary rock)
Sandstone (Ferruginous)
Arenite (Fe-rich)
Dendritic Jasper (River Stone)
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
Sandstone
Arenite (primarily SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Black Chert/Flint)
Silicon Dioxide (SiO2)
Belemnite (Fossilized Rostrum)
Belemnitida (order), specifically Neohibolites or similar genera depending on age
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Staghorn Coral Specimen
Acropora cervicornis (Calcium Carbonate, CaCO3)
Chert (containing a small fossil)
Microcrystalline Quartz (SiO2)
Mookaite Jasper
Silicon Dioxide (SiO2) with impurities