Pink coral and green-stone jewelry
Likely pink coral (calcium carbonate, CaCO₃) set with an unidentified green stone; the image is too indistinct to identify the green material reliably.
gemstone
Category
Organic Structure (Not A Rock)
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
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Red-and-green jasper
Jasper, microcrystalline quartz (SiO₂), colored mainly by iron oxides and possibly chlorite/epidote
mineral
Shale
Laminated Fissile Pelite
sedimentary
Bornite (“peacock ore”), likely weathered copper sulfide
Bornite, Cu₅FeS₄; possibly chalcopyrite, CuFeS₂, with iridescent tarnish
mineral
Chert (Green Fossilized Algae or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Fossiliferous Limestone
Carbonate Rock (CaCO3 with organic inclusions)
sedimentary
Clam Fossil
Bivalvia fossil
fossil
Fossiliferous Rock (Invertebrate Fossil in Matrix)
Fossiliferous limestone or shaly matrix containing skeletal fossil remains
fossil
Manganese Dendrite on Siltstone
Manganese Oxide (pyrolusite or psilomelane) Dendrites
mineral/sedimentary
Fossiliferous Limestone (Shell Fragment)
Biogenic Limestone (Calcium Carbonate / CaCO3)
sedimentary
Sedimentary Rock (Limestone or Siltstone pebble)
Sedimentary rock fragment
sedimentary
Possible smooth beach pebble (identity uncertain)
Unidentified fine-grained siliceous pebble; possibly chert or quartzite
sedimentary
Polished amber
Fossilized tree resin (primarily organic polymerized diterpenes)
gemstone
Chert / Jasper
Silicon Dioxide (SiO2)
sedimentary
Coal (Bituminous Coal)
Caustobiolith / Sedimentary Rock
sedimentary
Pink granite
Granitic rock, chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende
igneous
Rounded pink granite cobble
Granite, chiefly quartz–alkali feldspar–plagioclase–biotite
igneous
Lapis Lazuli
Lapis lazuli (Complex silicate rock containing Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2, Calcite, and Pyrite)
metamorphic
Weathered Sedimentary Rock
Sedimentary Rock
Sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (with Moss)
Quartz Arenite / Sandstone
sedimentary
Fossilized Coral
Cnidaria fossil / Calcite-replaced coral
fossil
Limestone with Fossil Fragments
Bioclastic Carbonate Rock (CaCO3)
sedimentary
Bituminous Coal
Organic sedimentary rock (humic coal)
sedimentary
Marine gastropod shell
Calcium-carbonate shell, primarily aragonite; species cannot be determined from the image
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Likely bituminous coal
Coal, predominantly maceral-rich carbonaceous material (composition varies)
sedimentary
Petrified Bone (Fossil Bone)
Per mineralization fossil bone (varies by organism, predominantly replacement by SiO2 - Quartz/Chalcedony)
fossil
Fossilized Shark Tooth
Chondrichthyes teeth
fossil
Fossilized Bone
Vertebrate Fossil (Biogenic sediment)
fossil
Dark speckled granite pebble
Granite, a quartz–feldspar–mica plutonic rock
igneous
Weathered granitic rock fragment
Granite, likely quartz–feldspar–biotite aggregate
igneous
Bauxite
Bauxite (principal ore of aluminum, primarily Al(OH)3)
sedimentary
Lapis Lazuli
Lazurite-dominant Metamorphic Rock (complex aluminosilicate)
metamorphic
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Agatized Fossil Coral
Agatized Anthozoa
fossil
Sandstone with Brachiopod Mold Fossil
Sedimentary rock (Sandstone) with indeterminate Brachiopod mold
fossil
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Petrified Wood
Silicified wood (SiO2)
fossil
Fossilized Shell Fragment
Invertebrate fossil (phylum Mollusca)
fossil
Weathered granite or granitic gneiss pebble
Granite: quartz + feldspar + mica; possibly weakly foliated gneiss
igneous