Coral Fossil
Anthozoa (Scleractinia)
fossil
Category
Marble
Browse marble specimens identified by the Rock Identifier community.
Brachiopod Fossil in Limestone
Phylum Brachiopoda, Class Rhynchonellata
sedimentary
Olivine (Peridotite)
(Mg, Fe)2SiO4 (Magnesium Iron Silicate)
igneous
Olivine (Peridotite)
(Mg,Fe)2SiO4 (Magnesium Iron Silicate)
igneous
Chert with Limestone matrix
Microcrystalline silica (SiO2) in Calcite (CaCO3) matrix
sedimentary
Limestone (specifically Bituminous or Carbonaceous Limestone)
Calcium Carbonate (CaCO3) with Organic Impurities
sedimentary
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Ammonite Fossil (Polished Half / Cleoniceras)
Ammonoidea (Subclass), often Cleoniceras genus; fossilized with Calcite (CaCO3) and Aragonite
Sedimentary
Diamond
Diamond (Carbon, C)
mineral
Narmada Lingam (Shiva Lingam)
Cryptocrystalline Quartz (Jasperiod / Chalcedony)
sedimentary
Aragonite
Aragonite (CaCO3)
mineral
Fossilized Echinoid
Echinoidea (likely of the order Echinoidea)
fossil
Chert (or Fossiliferous Limestone)
Microcrystalline Quartz (SiO2) / Calcium Carbonate (CaCO3)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Limestone with Calcite Veining
Calcium Carbonate (CaCO3)
sedimentary
Brachiopod Fossil in Shale
Phylum Brachiopoda (often species of Order Spiriferida or Rhynchonellida)
sedimentary
Fossilized Crinoid Stem Columnal
Phylum Echinodermata; Class Crinoidea (CaCO3)
sedimentary
Peridot
Olivine ((Mg, Fe)2SiO4)
gemstone
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclastic inclusions
sedimentary
Limestone with Chert or Siltstone bands
Sedimentary carbonate rock (CaCO3) often with siliceous impurities
sedimentary
Limestone (with potential fossil inclusions)
Calcium Carbonate (CaCO3)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Trilobite Pygidium (Tail Segment)
Phylum Arthropoda, Class Trilobita (likely order Phacopida)
sedimentary (fossil)
Oyster Shell (Aragonite/Calcite)
Calcium Carbonate (CaCO3)
sedimentary
Fossilized Coral
Cnidaria (Anthozoa), often replaced by Calcium Carbonate (CaCO3) or Silica (SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Pumice
Pumice (volcanic rock)
Igneous
Chert (or Flint)
Chert (microcrystalline or cryptocrystalline quartz, SiO2)
Sedimentary
Chert (Iron-Stained)
Chert (Silicon Dioxide, SiO2)
sedimentary
Fossilized Brachiopod
Brachiopoda (likely Order Spiriferida or Productida)
fossil
Limestone with fossil crinoid stems
Calcium Carbonate (CaCO3) containing Crinoidea fossils
sedimentary
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Fossilized Brachiopod
Articulata (Class) / Brachiopoda (Phylum)
sedimentary
Limestone with Algal/Lichen Colonization
Calcium Carbonate (CaCO3)
sedimentary
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
metamorphic
Coquina / Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Fossilized Sea Urchin (Echinoid)
Echinoidea (Class); commonly Clypeasteroida for sand dollar types
sedimentary (fossil)
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Organic Gemstone/Biomineral
Chert (varietal: Jasper or Flint likely, but definitive identification is difficult from image)
SiO₂ (silicon dioxide)
Sedimentary
Chert (often called Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Crinoid Stem Fossil
Crinoid Columnal (Phylum Echinodermata)
fossil
Fossiliferous Limestone with Crinoid Stem fragment
Calcite (CaCO3) containing Crinoidea fossils
sedimentary