Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
mineral
Category
Organic (Biological Organism)
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Quartzite and Milky Quartz River Pebbles
Silicon Dioxide (SiO2)
metamorphic
Chert (with Limestone and Iron Oxide staining)
Cryptocrystalline Quartz (SiO2)
sedimentary
Amber
Succinite (C10H16O)
gemstone
Fossiliferous limestone (likely ammonite/gastropod-bearing)
Bioclastic limestone; predominantly calcite (CaCO₃)
sedimentary
Fossiliferous limestone, likely coral or shell fragment
Calcitic limestone (primarily CaCO₃), containing preserved marine bioclasts
fossil
Calcite crystal
Calcite (calcium carbonate, CaCO₃)
mineral
Dyed Agate (Tumbled)
Silicon Dioxide (Chalcedony variety, artificially dyed)
gemstone
Quartzite Pebble with Pyrite Coating
SiO2 (Quartz) with FeS2 (Pyrite) inclusions or surface coating
metamorphic
Bivalve Fossil (Shell-bearing Sedimentary Rock)
Class Bivalvia (Phylum Mollusca) within a Calcarenite/Sandstone matrix
fossil
Amber
Fossilized Tree Resin (Successite)
fossil
Fossiliferous Limestone
Limestone (CaCO3 - Calcium Carbonate)
sedimentary
Amber
Succinite (C10H16O)
mineral
Dendritic Agate (Tree Agate)
Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions
mineral
Amber
Succinite
mineraloid
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
igneous
Pyrite in Shale
Iron Disulfide (FeS2) in Argillaceous Shale
sedimentary
Green Moss Agate
Agate (Silicon Dioxide - SiO2) with inclusions of hornblende or chlorite
mineral
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
sedimentary
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
mineral
Fossilized Gastropod Shell
Gastropoda (Class)
sedimentary
Fossilized Coral (Petoskey-like or Favosites)
Anthozoa (Fossilized Coral)
sedimentary
Tree Agate (or Moss Agate)
Dendritic Agate (Silicon Dioxide - SiO2)
mineral
Pink Opal
Hydrated Silica (SiO2·nH2O)
mineral
Ferruginous Sandstone (Ironstone)
Sedimentary rock with Limonite/Goethite cement
sedimentary
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
mineraloid
Amber
Succinite (specifically for Baltic amber; fossilized tree resin)
Organic (Sedimentary-associated)
Moss Agate and Hematite
Silica (SiO2) with fibrous inclusions of Manganese or Iron; Hematite (Fe2O3)
mineral
Natural or Cultured Pearl
Calcium Carbonate (Aragonite and Conchiolin), CaCO3
Mineral (Organic)
Baroque Pearl
Calcium Carbonate (Aragonite or Calcite) and Conchiolin
Organic Gemstone
Pearl (Cultured or Natural)
Aragonite (CaCO3) with Conchiolin
Organic Mineraloid
Amber (Cherry Amber)
Succinite (C10H16O)
Organic Gemstone
Paper (Cellulose)
Cellulose (C6H10O5)n
Organic (Anthropogenic)
Amber
Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)
Organic Mineraloid
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Organic mineraloid
Popcorn
Zea mays everta (P. Wilson) (Botanical name for the corn variety)
Organic/Biogenic
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Organic Mineraloid
Amber
Succinite (Fossilized Resin C10H16O)
Organic Mineraloid
Ambergris
Ambrein (C30H52O Derivative)
Organic (Zoogenic)
Pearl (Imitation or Cultured)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
Mineraloid (Organic)
Limestone (Weathered / Limonite-stained)
Sedimentary carbonate rock (CaCO3)
sedimentary