Geode (unopened)
Chert / Chalcedony Geode (SiO2)
Category
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
Bloodstone (also known as Heliotrope)
Silicon Dioxide (SiO2) - variety of Chalcedony
Ruby
Corundum (Al2O3:Cr)
Fossilized Bone Fragment
Permineralized Vertebrate Fossil (Hydroxyapatite replaced by Minerals)
Yellow Ochre / Limonite
Limonite (inter-mixed iron oxides and hydroxides, primarily FeO(OH)·nH2O)
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Geode with Quartz Crystal Cavity
Silicon Dioxide (SiO2) in Calcareous/Siliceous Matrix
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide / Chalcedony)
Amber
(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.
Amber
Succinite (Resinite)
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Amber (Copal)
Organic gemstone, fossilized tree resin (often immature amber or copal)
Amber
Succinite (specifically for Baltic amber); approximate formula C10H16O
Chert (Brecciated Chert)
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Pearl
Calcium Carbonate (Aragonite) - CaCO3
Fire Opal (in Matrix)
Hydrated Silica (SiO2·nH2O)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Bauxite Ore
Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)
Amber
Succinite (C10H16O)
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 principal component)
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula: SiO2)
Petrified Wood
Silicified wood (principally SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Amber
Succinite (specifically Baltic Amber) - Formula: C10H16O (approximate)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Flower Agate (Plume Agate)
Chalcedony (Silicon Dioxide) with Spherulitic Inclusions - SiO2
Sandstone (with carbonaceous plant fragments)
Arenite (composed primarily of SiO2)
Petrified Wood
Silicified Wood (SiO2)
Sandstone (likely Fossiliferous Sandstone)
Clastic sedimentary rock (primarily SiO2)
Clay (as a rock-forming material)
Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)
Dendritic Agate (Tree Agate)
Chalcedony (Silicon Dioxide, SiO2) with Manganese or Iron Oxide inclusions
Tree Agate (or Moss Agate)
Dendritic Agate (Silicon Dioxide - SiO2)
Clear Quartz Crystal
Quartz (Silicon Dioxide, SiO2)
Amber
Succinite (fossilized resin, C10H16O)
Amber
Succinite (Organic Mineraloid)
Chert (Yellow/Tan)
Microcrystalline Quartz (SiO2)
Moonstone
Orthoclase Feldspar ((K,Na)AlSi3O8)
Jasper
Jasper (Silicon Dioxide, SiO2)