Organic Mineraloid And Mineral

Moss Agate

Cryptocrystalline Quartz (SiO2 with manganese or iron oxide inclusions)

Black Pearl (Tahitian-style Cultured Pearl)

Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)

Coprolite

Coprolite (fossilized feces)

Dinosaur Fossil (Skull)

Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)

Petrified Wood

Silicified Wood (primarily SiO2)

Geode with Quartz Crystal Cavity

Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix

Petrified Wood

Silicified wood (primarily Quartz/Chalcedony, SiO2)

Geode (Unopened)

Silica-rich concretion (SiO2)

Chert Nodule

Microcrystalline Silica (SiO2)

Fossilized Shark Tooth (Fragment)

Elasmobranchii fossil (likely Cretalamna or Squalicorax genus)

Chert (Green Chert/Jasper)

Chert (primarily Microcrystalline Quartz, SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (specifically Yellow/Honey Jasper variety)

Cryptocrystalline Quartz (SiO2)

Petrified Wood

Siliconized Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Petrified Wood

Silicified Wood (SiO2)

Jasper (Petrified Wood variant)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone Concretion

Arenaceous concretion (primarily SiO2 with Fe2O3 staining)

Chert (Septarian or Nodular variety)

Microcrystalline Quartz (SiO2)

Calcite

Calcium Carbonate (CaCO3)

Dendritic Moss Agate

Chalcedony (Silicon Dioxide, SiO2) with inclusions

Ironstone Concretion (Limonite/Hematite Nodules)

Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)

Chert (specifically Blue Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Jasper with Quartz Vein

Silicon Dioxide (SiO2) with impurities

Sandstone Concretion

Clastic sedimentary rock (primarily Quartz SiO2)

Sandstone (with carbonaceous plant fragments)

Arenite (composed primarily of SiO2)

Chert (vuggy variety)

Microcrystalline silica (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Limonite (Iron Ore)

Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)

Chert (Septarian or Banded Nodular Variety)

Microcrystalline Quartz (SiO2)

Shale

Fissile Mudstone (Shale)

Natural or Cultured Pearl

Calcium Carbonate (Aragonite and Conchiolin), CaCO3

Chert / Chalcedony

Microcrystalline Quartz (SiO2)

Jasper

Microcrystalline Quartz (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Chert / Jasper

Silicon Dioxide (SiO2)

Amber

Succinite (amorphous organic polymer)

Rough Amber (likely Copal or immature Amber)

Organic gemstone / Succinite (if Baltic)

Amber

Amber (Amorphous Organic Hydrocarbon)

Amber

Succinite (a fossilized organic resin)