Granite
Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)
Category
Browse mineraloid (man made) specimens identified by the Rock Identifier community.
Granite
Granite (a common rock name, not a single mineral species, composed primarily of quartz, feldspar, and mica/amphibole)
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
White Precious Opal
Hydrated Silica (SiO2·nH2O)
Obsidian
Volcanic glass (high silica volcanic rock)
Pearl
Organic Mineraloid (CaCO3 + Conchiolin)
Pearl
Aragonite and Conchiolin (CaCO3 + organic protein)
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Black Pearl (Tahitian Type)
Aragonite / Conchiolin composite (CaCO3)
Amber
Succinite (fossilized resin); C10H16O
Amber
Succinite (approximate formula C10H16O)
Chalk
Carbonate rock (mainly CaCO3)
Black Pearl (Tahitian or Irradiated Type)
Organic gemstone (Calcium Carbonate with Conchiolin Binding)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Amber
Succinite (C10H16O)
Diamond (in Jewelry)
Carbon (C)
Slag (Industrial Glass)
Anthropogenic Amorphous Vitreous Silicate
Obsidian
Volcanic Glass (predominantly SiO2, approximately 70% or more)
Chert (Flint)
Silicon Dioxide (SiO2)
Natural White Pearl
Calcium Carbonate (Aragonite/Calcite) with Conchiolin - CaCO3
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
Amber
Succinite (fossilized resin)
Amber (with potentially inclusions)
Succinite (Fossilized Tree Resin)
Cobalt Blue Slag Glass
Amorphous Silicon Dioxide (anthropogenic) with Cobalt additives
Amber
Succinate (Fossilized Tree Resin)
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
Jade (likely Jadeite or Nephrite)
Jadeite (NaAlSi2O6) or Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)
Sandstone
Arenite
Prasiolite and Quartz Crystal Cluster
Quartz (SiO2); Prasiolite is a variety of Quartz
Diamond
Diamond (pure Carbon, C)
Amber
Succinite (fossilized tree resin)
Pearl (Biogenic Mineral)
Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3
Sandstone
Arenite (composed primarily of SiO2)
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Diamond
Diamond (pure Carbon, C)
Diamond
Diamond (pure carbon C)
Sandstone
Arenite (variable SiO2 composition)
Sandstone
Arenite (primarily SiO2)
Smoky Quartz Cluster
Smoky Quartz (Silicon Dioxide - SiO2)