Pink Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Category
Browse organic (geological interest) specimens identified by the Rock Identifier community.
Pink Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Limonite
Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)
Pyrite
Iron Sulfide (FeS2)
Seashell Fragment
Calcium carbonate (CaCO3) - primarily Aragonite or Calcite
Banded gneiss pebble
Gneiss, likely quartz–feldspar–mica gneiss
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide with Iron Oxide (SiO2 with traces of Fe2O3/FeO(OH))
Pyrite
Iron Disulfide (FeS2)
Amber
Resinite / Fossilized Tree Resin
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
Pyrite
Iron Sulfide (FeS2)
Blue Apatite
Apatite group (Ca5(PO4)3(F,Cl,OH))
Iron-rich quartzite or weathered ironstone pebble
Quartzite, chiefly SiO₂, with iron-oxide minerals (hematite/goethite)
Naga Silver-Inlaid Ebony and Bone/Horn Beads
Diospyros (Ebony) or Keratin (Horn) with Silver/White-Metal Inlay
Freshwater Pearl
Aragonite / Biogenic Calcium Carbonate (CaCO3)
Hypersthene
Hypersthene ((Mg,Fe)SiO₃)
Limestone (or Calcite Pebble)
Calcium Carbonate (CaCO3)
Chert
Chert (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Chert Pebble
Microcrystalline Quartz (SiO2)
Banded Chert
Silicon Dioxide (SiO2)
Mother of Pearl and Onyx
Aragonite (Mother of Pearl) and Chalcedony (Onyx)
Quartz-veined Limestone
Sedimentary limestone with quartz/calcite veinlets
Chert Pebble
Chert (SiO2)
Smurf Rock (Fictional Interpretation)
Cyanus Anthropomorphicus (Geologic Simulation)
Pearls (likely freshwater cultured pearls)
Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin
Chert (Flint)
Silicon Dioxide (SiO2)
Desert Rose Fragment (Atypical) / Weathered Chert
Silicon Dioxide (SiO2) or Barium Sulfate (BaSO4) depending on exact mineralogy
Chert
Microcrystalline Quartz (SiO2)
Chert (Jasper variation)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Weathered basalt or mafic metavolcanic rock
Basalt, possibly altered to greenstone (chlorite–epidote–actinolite assemblage)
Quartz (in matrix)
Quartz (SiO₂)
Amber
Succinite (Approximate formula: C10H16O)
Jasper
Silicon Dioxide (SiO2) with impurities
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Ferruginous Sandstone Concretion (Ironstone Phosphorite)
Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)
Chalcopyrite
CuFeS2
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Smooth River Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Glauconitic Sandstone
Glauconitic Quartz Arenite
Chert (specifically Flint or Jasper variant)
Microcrystalline quartz (SiO2)