Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Category
Organic Gemstone (Fossilized Resin)
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
Dendrite (Manganese Oxide Dendrites)
Psilomelane or Pyrolusite on Matrix (typically MnO2)
mineral
Milky Quartz with Dendritic Inclusions
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
mineral
Synthetic Marbled Aggregate (Footwear Component)
Ethylene-vinyl acetate (Croslite™)
not a rock (man-made polymer)
Petoskey Stone
Hexagonaria percarinata (Fossilized Coral)
sedimentary
Coprolite
Fossilized feces (various taxa)
sedimentary
Spinosaurus Tooth
Spinosaurus aegyptiacus (fossilized in Hydroxyapatite)
sedimentary
Horn Coral Fossil
Rugosa (extinct order of solitary corals)
sedimentary
Pearl
Aragonite (CaCO3 with conchiolin)
mineral
Ammonite Fossil
Ammonoidea (primarily composed of Calcite, CaCO3)
sedimentary
Limestone (Flagstone)
Fossiliferous Limestone (CaCO3)
sedimentary
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
mineraloid
Turquoise and Spiny Oyster (Heishi style beads)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Spondylus (Spiny Oyster shell)
mineral and organic gemstone
Black Pearl (Tahitian or Irradiated Type)
Organic gemstone (Calcium Carbonate with Conchiolin Binding)
mineraloid
Fossilized Brachiopod
Brachiopoda (Class Rhynchonellata or Spiriferida)
sedimentary
Fulgurite
Fulgurite (Lechatelierite), amorphous SiO2
metamorphic
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
sedimentary
Bamboo Leaf Jasper
Silicified Siltstone or Jasper (SiO2)
sedimentary
Tree Agate
Dendritic Chalcedony (SiO2)
sedimentary
Fossilized Rugose Coral (Petoskey Stone precursor)
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Turquoise and Red Coral
Turquoise: CuAl6(PO4)4(OH)8·4H2O; Red Coral: Corallium rubrum (organic gemstone)
mineral
Petoskey Stone
Hexagonaria percarinata
sedimentary
Mammoth Tooth Fragment
Mammuthus primigenius (fossilized dentin and enamel)
sedimentary
Quartzite Cobble
Quartzite (SiO2)
metamorphic
Oyster Shell (Aragonite/Calcite)
Calcium Carbonate (CaCO3)
sedimentary
Fossilized Coral (Petoskey Stone or similar)
Hexagonaria percarinata (Order: Rugosa)
sedimentary
Cultured Marble (Synthetic)
Polymer-matrix composite (typically calcium carbonate in polyester resin)
Synthetic / Composite Material
Belemnite Fossil
Belemnitida (extinct order of Cephalopods)
sedimentary
Belemnoit (Fossil)
Belemnoidea (Order), Rostrum / Guard
sedimentary
Red Shale
Lutite (primarily composed of Hydrous Aluminum Silicates with Hematite staining)
sedimentary
Petoskey Stone
Hexagonaria percarinata (Fossilized Coral)
sedimentary
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
mineral
Chakra Stone (Composite / Man-made Bonded Gemstones)
Composite of Quartz, Lapis Lazuli, Aventurine, Tiger's Eye, and Jasper (SiO2, (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, etc.)
Combined Minerals / Metaphysical stones
Sulfur (with possible Cullet Glass or Slag imitation)
Native Sulfur (S8)
mineral
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Sandstone
Arenite (SiO2 based)
sedimentary
Kambaba Jasper
Stromatolite / Fossilized Algae (Rhyolitic structure)
sedimentary
Quartz Vein in Pelite (Metamorphic Rock)
Hydrothermal Quartz Veining in Metasedimentary Rock (SiO2)
metamorphic
Ironstone Concretion (Pot Stone)
Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)
sedimentary