Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Category
Mineral (Biogenic)
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Fossiliferous Limestone
Calcium Carbonate (CaCO3) matrix with biogenic fragments
fossil
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock / CaCO3 with fossil fragments
sedimentary
Coquina
Biogenic Limestone (mostly Calcium Carbonate, CaCO3)
sedimentary
Devil's Toenail
Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)
sedimentary
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
sedimentary
Flint or chert fragment
Microcrystalline quartz (SiO₂), likely flint/chert
sedimentary
Sand dollar fossil
Clypeasteroida (echinoid test), commonly Clypeasteroides spp.
fossil
Chert (likely brown flint)
Microcrystalline quartz, SiO₂ (chalcedonic quartz aggregate)
sedimentary
Chert or microcrystalline quartz fragment
Chert; cryptocrystalline SiO₂, possibly chalcedony-rich
sedimentary
Chert or flint (weathered brown variety)
Microcrystalline quartz, SiO₂ (chalcedonic quartz)
sedimentary
Tumbled dark flint/chert
Microcrystalline quartz (SiO₂), commonly with chalcedony and iron-oxide impurities
sedimentary
Chert (Flint / Chalcedony pebble)
Silicon Dioxide (SiO2)
sedimentary
Chert or flint with chalcedony/quartz veins
Microcrystalline silica: primarily quartz (SiO₂), including chalcedony; possible fossiliferous limestone or silicified material
sedimentary
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Chert (likely jasper-bearing chert)
Microcrystalline quartz (SiO₂), with iron-oxide staining and possible chalcedony
sedimentary
Pearl necklace
Pearl: biogenic calcium carbonate, primarily aragonite (CaCO₃), in a conchiolin matrix
gemstone
Fossil Coral
Coral Limestone (a type of biogenic sedimentary rock)
Sedimentary
Chalk / Sedimentary Limestone
Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock
sedimentary
Fossiliferous Limestone
Biogenic Limestone containing marine invertebrate fossils
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone / Fossil Fragment
Calcium Carbonate Matrix with Biogenic Inclusions (CaCO3)
fossil
Fossiliferous Limestone / Fossil Fragment
Calcium Carbonate (CaCO3) with indeterminate biogenic remains
fossil
Fossiliferous Limestone (or Bryozoan/Coral Fossil Pebble)
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate with Fossils)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Stromatolite
Biogenic Sedimentary Rock (Lithified microbial mat)
sedimentary
Chalk (Calcitic)
Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock
sedimentary
Stromatolite
Biogenic Sedimentary Rock (Precambrian Stromatolite fossil)
sedimentary
Stromatolite
Laminated biogenic sedimentary structure (formed by Cyanobacteria)
sedimentary
Weathered chert or silicified limestone nodule
Microcrystalline quartz (SiO₂), possibly with calcite (CaCO₃)
sedimentary
Flint or chert fragment
Microcrystalline quartz (SiO₂), typically chalcedony with possible impurities
sedimentary
Chert
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Flint or chert
Microcrystalline quartz (SiO₂), likely gray chert/flint
sedimentary
Chert or flint fragment
Microcrystalline quartz (SiO₂), possibly iron-stained chert
sedimentary
Cat's Eye Shell (Shiva Shell)
Operculum of the Turbo petholatus (Tapestry Turban Snail), predominantly Calcium Carbonate (Aragonite)
mineraloid / biogenic specimen
Fossiliferous Limestone
CaCO3 (principally Calcite or Aragonite)
sedimentary
Hag Stone (Holey Rock / Fossiliferous Limestone)
Limestone (CaCO3) with natural erosion / fossil cavities
sedimentary
Scallop Shell Fossil
Pecten sp.
fossil
Pearl (Imitation or Cultured)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
Mineraloid (Organic)