Precious Red Coral
Corallium rubrum / Corallium japonicum
mineral (organic gemstone)
Category
Mineral Like Biological Tissue
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Learn about Mineral Like Biological Tissue in the encyclopedia
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Pyrite
Iron Sulfide (FeS2)
mineral
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
mineral
Amber
Succinite (organic hydrocarbon)
mineraloid
Fossil Shark Tooth
Squalicorax (likely Squalicorax pristodontus or Squalicorax falcatus)
fossil
Amber
Succinite (fossilized resin)
mineral
Possible fossilized bone fragment
Indeterminate fossil bone; no species can be identified from this image
fossil
Fossiliferous limestone, possibly a weathered shell or bone fragment
Calcite (CaCO₃) fossil material in limestone; exact fossil identification is uncertain from the image
fossil
Limitation Concretion
Ironstone Concretion (Goethite/Limonite)
sedimentary
Obsidian
Volcanic Glass (SiO2)
igneous
Amber
Succinite (Fossilized Resin)
fossil
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Fossil Coral (Petoskey Stone / Hexagonaria)
Hexagonaria percarinata (Silicified/Calcite Replacement Coral)
fossil
Petrified wood
Silicified fossil wood, commonly quartz/chalcedony (SiO₂) replacing woody tissue
fossil
Gravel or Pebble
Clastic Sedimentary Grain (typically composed of Quartz or Silicate minerals)
sedimentary
Petrified Wood
Silicified wood (Quartz/Chalcedony replacement)
fossil
Amber
Succinates (Fossilized Tree Resin)
fossil
Sandstone (with biological crust)
Arenite (SiO2 based)
sedimentary
Pearl
Calcium Carbonate (Aragonite) - CaCO3
mineral
Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin (CaCO3)
mineral
Pearl (as a Biogenic Mineral)
Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3
mineral
Chert (with potential fossil inclusion)
Microcrystalline Quartz (SiO2)
sedimentary
Kidney Stone
Calcium Oxalate (CaC2O4·nH2O)
mineral
Limonite (Hydrated Iron Oxide / Bog Iron)
FeO(OH)·nH2O
Mineral (Sedimentary context)
Limestone with Lichen/Algae
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Pearl
Aragonite (CaCO3 with conchiolin)
mineral
Pearl (Biogenic Mineraloid)
Calcium carbonate (Aragonite) and Conchiolin, CaCO3
mineral
Pearl
Calcium Carbonate (CaCO3)
mineral
Sandstone with Algae Growth
Arenite with Chlorophyta/Lichen
sedimentary
Sandstone concretion
Arenite sedimentary rock (concretion/nodule)
sedimentary
Pearl
Organic Mineral (CaCO3 with conchiolin)
mineral
Tumbled moss agate (likely dendritic/chalcedony agate)
Microcrystalline quartz, SiO₂, with iron/manganese-rich inclusions
mineral
Petrified Wood
Silicified Wood (primarily SiO2)
sedimentary
Fossilized Shark Tooth (Partial) or Coprolite
Elasmobranchii (fossil) or Coprolite (trace fossil)
fossil
Pearl
Calcium Carbonate (CaCO3) in the form of orthorhombic Aragonite and Conchiolin
mineral
Amber (Copal)
Succinite (fossilized tree resin)
mineral
Amethyst
Amethyst (Silicon Dioxide, SiO2 + Fe)
mineral
Amber
Succinite (specifically Baltic Amber) - Formula: C10H16O (approximate)
Organic Mineraloid
Petrified Wood
Silicified Wood (SiO2 permineralization)
sedimentary
Fossil Coral
Anthozoa (Scleractinia)
fossil
Chert with Iron Oxide Staining
Microcrystalline Quartz (SiO2) with Limonite/Goethite staining
sedimentary
Amber
Succinate (Succinite for Baltic varieties)
Organic Mineraloid