Chert (Common Opal/Agatized Rock)
Microcrystalline Quartz (SiO2) with potential Chalcedony/Opaline silica
sedimentary
Category
Organic Mineral
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Chert (containing Iron Oxide)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper/Mudstone)
Microcrystalline Quartz (SiO2)
sedimentary
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
sedimentary
Chert (specifically Flint or Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Amber (fossilized tree resin)
Succinite; organic resin composed mainly of polymerized terpenoids
fossil
Fossil bivalve shell
Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features
fossil
Dyed Agate (Tumbled)
Silicon Dioxide (Chalcedony variety, artificially dyed)
gemstone
Banded sandstone pebble
Lithified quartz–feldspar sandstone, likely ferruginous and carbonaceous laminae
sedimentary
Shale
Shale (Fine-grained clastic sedimentary rock)
sedimentary
Shungite
Fullerene-bearing carbonaceous rock
mineral
Petrified Wood
Silicified Wood (SiO2)
mineral
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineral
Pyrite Geode (Sparkling Druzy)
Iron Sulfide (FeS2) in Sedimentary Nodule
mineral
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions
mineral
Moss Agate
Chalcedony (Silicon Dioxide) with dendritic inclusions (SiO2)
Mineral
Chert (concretionary/nodular variant)
Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions
sedimentary
Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin
gemstone
Fossilized Shark Tooth (Megalodon or Carcharocles fragment)
Elasmobranchii (Fossilized tooth root / crown section)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Chert (Flint variety)
Microcrystalline context of Quartz (SiO2)
sedimentary
Tonsil Stone (Tonsillolith)
Calcium phosphate / Calcium carbonate biomineral
mineral
Chert (Sedimentary Rock)
Silicon Dioxide (SiO2)
sedimentary
Graphite
Graphite (Native Carbon), Formula: C
Metamorphic
Bivalve seashell
Calcareous shell, primarily aragonite (CaCO₃); likely a modern cockle or related bivalve
fossil
Petrified Wood
Silicified Wood (SiO2 permineralization)
fossil
Chert (Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Petrified Wood
Silicified Wood (primarily SiO2)
fossil
Banded Chert
Silicon dioxide (SiO2)
sedimentary
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 principal component)
sedimentary
Chert Pebble
Microcrystalline Quartz (SiO2)
sedimentary
Red coral cabochon (likely dyed or reconstructed coral)
Corallium rubrum or other calcareous coral; chiefly aragonite (CaCO₃)
gemstone
Fossilized Shark Tooth
Fossilized elasmobranch tooth (Apatite/Calcium Phosphate)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Petrified Wood
Silicified wood (primarily quartz replacing organic cellulose)
fossil
Banded Sedimentary Rock (Siltstone/Mudstone with concretion)
Siltstone with Ferruginous Banding
sedimentary
Chert (specifically Brown Chert or Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Chert with Quartz/Calcite Vein
Microcrystalline Silica (SiO2)
sedimentary
Sandstone with Vitrinite/Coal inclusions
Arenite with Carbonaceous inclusions
sedimentary
Mammoth Tooth
Mammuthus primigenius (Tooth fragment)
fossil