Shell Cameo (Sardonyx Shell)
Cassis madagascariensis (Sardonyx shell)
mineral (biogenic silica/calcium carbonate substrate)
Category
Mineral (Biogenic Silica
Browse mineral (biogenic silica specimens identified by the Rock Identifier community.
Learn about Mineral (Biogenic Silica in the encyclopedia
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Spiny Oyster Shell
Spondylus (Calcium Carbonate, CaCO3)
mineral
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
sedimentary
Kidney Stone
Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)
mineral
Chert (Yellow Jasper / Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Pearl jewelry
Pearl (biogenic calcium carbonate, primarily aragonite, CaCO₃)
gemstone
Pearl
Aragonite (CaCO3) with Conchiolin
mineral
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Seashell (Calcium Carbonate)
Calcium Carbonate (CaCO3)
mineral
Fossilized Bone
Petrified Bone / Biogenic Sedimentary
fossil
Chert (Agate / Jasper pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Pebble)
Microcrystalline Quartz (SiO2)
sedimentary
Pearl (as a Biogenic Mineral)
Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3
mineral
Abalone Shell (Nacre)
Aragonite (CaCO3) - Biogenic Mineral
mineral
Chert (Nodule)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Chert (with Iron Staining)
Microcrystalline Quartz (SiO2)
sedimentary
Green Chert
Microcrystalline Quartz (SiO2)
sedimentary
Cleavable Calcite
Calcium Carbonate (CaCO3)
mineral
Brachiopod Fossil
Phylum Brachiopoda (likely Order Rhynchonellida or Spiriferida)
sedimentary
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
mineral
Banded Chert / Agate
Silicon Dioxide (SiO2)
sedimentary
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper / Iron-stained Chert)
Microcrystalline Quartz (SiO2 with Fe-oxides)
sedimentary
Chert
Chert (SiO2)
sedimentary
Fossilized Tooth Fragment
Vertebrate Fossil (Mammalia indet.)
fossil
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Fossilized tooth or jaw fragment (likely fish or reptile)
Indeterminate vertebrate bone/tooth; mineralized hydroxyapatite, commonly Ca₅(PO₄)₃(OH)
fossil
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Sea Snail Shell (Top Shell)
Trochidae family (Calcium Carbonate, CaCO3)
mineral
Chert (Flint / Jasper / Hornstone)
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Tooth
Vertebrate Fossilized Tooth (Mineralized Biogenic Material)
fossil
Seashell Fragment (Aragonite/Calcite)
Calcium Carbonate (CaCO3) - Shell fragment
sedimentary
Banded chert or flint
Microcrystalline quartz (SiO₂), likely with iron-oxide and dark organic/mineral impurities
sedimentary
Chert (Arrowhead Point)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Pearl (as a biogenic mineral/gemstone)
Calcium Carbonate (mostly Aragonite), CaCO3
mineral
Mother of Pearl (Nacre)
Aragonite with Conchiolin (CaCO3)
mineral
Chert (likely chalcedony-rich flint)
Microcrystalline quartz, SiO₂ (quartz/chalcedony)
sedimentary
Chert Pebble with Quartz Veining
Microcrystalline Quartz (SiO2)
sedimentary