Chert (Flint)
Microcrystalline Quartz (SiO2)
Category
Browse organic gemstone specimens identified by the Rock Identifier community.
Chert (Flint)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
Chert (often called Flint in this context)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variation)
Chert (SiO2)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Lightly weathered variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Amber
Succinicum (Succinite); C10H16O
Chert (Black Flint)
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone
Limestone (CaCO3 - Calcium Carbonate)
Dendritic Agate (Tree Agate)
Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions
Amber
Succinite (C10H16O)
Pyrite in Shale
Iron Disulfide (FeS2) in Argillaceous Shale
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
Shale (or Mudstone)
Siltstone/Argillite (composed mainly of clay and silt-sized particles)
Green Moss Agate
Agate (Silicon Dioxide - SiO2) with inclusions of hornblende or chlorite
Tree Agate (or Moss Agate)
Dendritic Agate (Silicon Dioxide - SiO2)
Pink Opal
Hydrated Silica (SiO2·nH2O)
Ferruginous Sandstone (Ironstone)
Sedimentary rock with Limonite/Goethite cement
Petrified Wood
Silicified Wood (SiO2)
White Topaz
Al2SiO4(F,OH)2
Coral Fossil (Scleractinia)
Scleractinia (Order), primarily CaCO3 (Aragonite or Calcite)
Amber
Fossilized Tree Resin (Amorphous Hydrocarbon)
Fossil Shell (Bivalve)
Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3
Red Jasper with Fossils
Silicified Fossiliferous Jasper (Chert variant, SiO2)
Shale
Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)
Beaded Jewelry (Assorted Gemstones)
Various minerals, including but not limited to Quartz (SiO2), Garnet (X3Y2(SiO4)3), Jade (Na(Al,Fe)Si2O6), Amethyst (SiO2),等の多様な組み合わせ
Limestone
Calcium Carbonate (CaCO3)
Fossilized Bone (Petrified Bone)
Permineralized Vertebrate Remains
Carnelian
SiO2 (Silicon Dioxide with Iron Oxide impurities)
Petrified Wood
Silicified Wood (SiO2)
Slate
Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)
Petrified Wood
Silicified Wood (SiO2)
Shale or Slaty Mudstone
Argillaceous sedimentary rock
Smoky Quartz
Silicon Dioxide (SiO2)
Septarian Nodule
Septarian Concretion (CaCO3 + Hydrated SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Shark Tooth Fossil
Elasmobranchii dentition (fossilized)
Fossil Shark Tooth Fragment
Elasmobranchii dentition (fragment)
Fossilized Shark Tooth (Otodus)
Otodus obliquus
Chert (Jasper)
Sedimentary Cryptocrystalline Quartz (SiO2)