Obsidian
Volcanic Glass (Amorphous silicon dioxide with trace impurities)
Category
Browse mineraloid (man made glass) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (Amorphous silicon dioxide with trace impurities)
Pearl
Biogenic CaCO3 (Aragonite and Calcite)
Pearl and Garnet Glass
Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass
Mixed polished gemstone and mineral collection
Primarily quartz varieties (SiO₂), plus probable aventurine, rose quartz, amethyst, agate, jasper, serpentine, feldspar, and possibly dyed or man-made glass pieces
Red Sandstone
Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)
Common Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Chert (Flint / Quartz Nodule)
Microcrystalline Quartz (SiO2)
Weathered chert or chalcedony nodule
Microcrystalline quartz (SiO₂), possibly silicified limestone or agate-like chalcedony
Polished black stone sphere (likely black basalt or black tourmaline)
Most likely fine-grained basalt (plagioclase–pyroxene); mineral identification is uncertain from the image alone
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite/Goethite Concretion
Hydrated Iron(III) Oxide-hydroxide (FeO(OH)·nH2O)
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite (Iron Ore)
Limonite (Hydrated iron oxide - FeO(OH)·nH2O)
Amber (Copal)
Succiniferous Resin
Amber
Succinate (Fossilized Tree Resin)
Amber (Copal)
Fossilized Tree Resin
Green Opal
Hydrated amorphous silica (SiO2·nH2O) with inclusions
Amber (Copal)
Succinate (Fossilized Resin)
Amber
Succinite (fossilized resin)
Shungite
Carbonaceous rock (primarily amorphous carbon)
Amber
Succinite (Resinite)
Common Opal
SiO2·nH2O (Hydrated Silicon Dioxide)
Green Opal
Hydrated amorphous silica (SiO2·nH2O)
Amber
Amber (Succinite), fossilized tree resin
Conch Pearl
Calcareous concretion (CaCO3)
Amber
Succinite (approximate formula C10H16O)
Amber
Succinite (fossilized resin); C10H16O
Amber / Copal
Succinite (fossilized tree resin)
White Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Amber
Succinite (approximate formula C10H16O)
Amber
Succinite
Pearls
Aragonite (calcium carbonate) and Conchiolin
Black Opal
Hydrated silica (SiO2·nH2O)
Amber
Succinite (C10H16O)
Amber
Succinite (Fossilized Tree Resin)
Amber
Succinite (specifically for Baltic amber); approximate formula C10H16O
Amber (Raw)
Succinite (Fossilized Resin)
Amber
Succinurite (C10H16O)
Opal
Hydrated silica (SiO2·nH2O)
Amber (with potentially inclusions)
Succinite (Fossilized Tree Resin)
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)