Shell Cameo (Sardonyx Shell)
Cassis madagascariensis (Sardonyx shell)
Category
Browse mineral (biogenic silica specimens identified by the Rock Identifier community.
Shell Cameo (Sardonyx Shell)
Cassis madagascariensis (Sardonyx shell)
Spiny Oyster Shell
Spondylus (Calcium Carbonate, CaCO3)
Kidney Stone
Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Chert (Yellow Jasper / Flint)
Microcrystalline Quartz (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Pearl
Aragonite (CaCO3) with Conchiolin
Seashell (Calcium Carbonate)
Calcium Carbonate (CaCO3)
Chert (Pebble)
Microcrystalline Quartz (SiO2)
Chert (with Iron Staining)
Microcrystalline Quartz (SiO2)
Pearl (as a Biogenic Mineral)
Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3
Chert (Agate / Jasper pebble)
Microcrystalline Quartz (SiO2)
Cleavable Calcite
Calcium Carbonate (CaCO3)
Brachiopod Fossil
Phylum Brachiopoda (likely Order Rhynchonellida or Spiriferida)
Chert (Nodule)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
Green Chert
Microcrystalline Quartz (SiO2)
Fossilized Tooth Fragment
Vertebrate Fossil (Mammalia indet.)
Banded Chert
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Banded Chert / Agate
Silicon Dioxide (SiO2)
Fossilized Bone
Petrified Bone / Biogenic Sedimentary
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
Chert (Jasper / Iron-stained Chert)
Microcrystalline Quartz (SiO2 with Fe-oxides)
Chert
Chert (SiO2)
Sea Snail Shell (Top Shell)
Trochidae family (Calcium Carbonate, CaCO3)
Chert (Flint / Jasper / Hornstone)
Microcrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Seashell Fragment (Aragonite/Calcite)
Calcium Carbonate (CaCO3) - Shell fragment
Banded chert or flint
Microcrystalline quartz (SiO₂), likely with iron-oxide and dark organic/mineral impurities
Chert (Arrowhead Point)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Abalone Shell (Nacre)
Aragonite (CaCO3) - Biogenic Mineral
Green Chert (Jasper / Flint)
Silicon Dioxide (SiO2)
Flint or chert fragment
Microcrystalline quartz (SiO₂), commonly chalcedony with possible iron-oxide impurities
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Pebble)
Silicon Dioxide (SiO2)
Chert (Flint / Agate Nodule)
Silicon Dioxide (SiO2)
Jasper (or Chert)
Microcrystalline Quartz (SiO2)
Fossilized Tiger Shark Tooth
Galeocerdo cuvier (fossilized hydroxylapatite)