Chert (often called Flint in various colors)
Silicon Dioxide (SiO2)
sedimentary
Category
Organic Gemstone (Not A Rock)
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
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Fossiliferous Limestone (Coquina)
Calcite (CaCO3) with Bioclastic inclusions
sedimentary
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
mineral
Chalcedony (Common Agate)
Silicon Dioxide (SiO2)
mineral
Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Shale or Slate
Shale (Sedimentary) or Slate (Metamorphic)
sedimentary or metamorphic
Dark gray flint or chert fragment
Microcrystalline quartz (SiO₂), commonly with minor chalcedony and impurities
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Limestone with Calcite Veins
Calcium Carbonate (CaCO3)
sedimentary
Chert (Jasper)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper/Flint Pebble)
Microcrystalline quartz (SiO2)
sedimentary
Limestone with Lichen
Calcium Carbonate (CaCO3) with Endolithic/Epilithic Lichen
sedimentary
Lapis Lazuli
Lazurite-rich metamorphic rock (approx. (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
metamorphic
Chert (often called Flint when found in chalk)
Microcrystalline Quartz (SiO2)
sedimentary
Black Mountain Stone (Seiryu Stone)
Limestone with Calcite veins (CaCO3)
sedimentary
Jasper
Silicon Dioxide (SiO2)
sedimentary
Lapis Lazuli
Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)
metamorphic
Amber
Succinite (specifically for Baltic amber); chemical formula approx. C10H16O
Organic Gemstone (fossilized resin)
Amber
Succinite (approximate formula C10H16O)
mineral
Amber
Succinicum (Organic polymer, largely C10H16O)
Organic Mineral
Amber
Fossilized Tree Resin
gemstone
Amber
Succinates (Organic compound: C10H16O)
mineraloid
Amber
Succinite (fossilized tree resin)
fossil
Amber
Succinite (fossilized organic resin)
mineral
Baltic Amber
Succinite (Fossilized Resin)
fossil
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Chert (Nodule)
Microcrystalline or Cryptocrystalline Silica (SiO2)
sedimentary
Bivalve seashell
Calcareous shell, primarily aragonite (CaCO₃); likely a modern cockle or related bivalve
fossil
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Fossilized Bone Fragment
Vertebrate Fossil
fossil
Amber
Succinite (C10H16O)
gemstone
Quartz-veined Limestone
Sedimentary limestone with quartz/calcite veinlets
sedimentary
Sandstone
Arenite
sedimentary
Chert / Flint
Silicon Dioxide (SiO2)
sedimentary
Fossil Coral / Crinoid Stem section
Anthozoa / Crinoidea fossil
fossil
Pearl
Calcium Carbonate (Aragonite) with Conchiolin; formula: CaCO3
mineral
Jasper
Silicon Dioxide (SiO2) microcrystalline quartz
sedimentary
Amber
Succinite (approximate formula C10H16O)
mineral
Chert (Yellow Jasper variant)
Silicon Dioxide (SiO2)
sedimentary
River-worn Chert
Microcrystalline Quartz (SiO2)
sedimentary
Weathered fossil fragment, possibly bone
Indeterminate fossilized bone; likely mineralized vertebrate bone (apatite-rich)
fossil