Limestone
Calcium Carbonate (CaCO3)
Category
Browse anthropogenic (man made material) specimens identified by the Rock Identifier community.
Limestone
Calcium Carbonate (CaCO3)
Limestone
Calcium Carbonate (CaCO3)
Granite (Dioritic variant)
Granite (Phaneritic Igneous Rock)
Quartzite Pebble
Metamorphic Quartz (SiO2)
Red jasper (tumbled)
Jasper, microcrystalline quartz/chalcedony (SiO₂) colored mainly by iron oxides
Quartz-rich gravel fragment
Quartz (silicon dioxide, SiO₂), possibly with feldspar or carbonate inclusions
Petrified Wood
Silicified wood (SiO2)
Petrified Wood
Silicified wood (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Diamond
Carbon (C)
Serpentinite
Serpentinite (Hydrous magnesium iron phyllosilicate)
Precious Opal in Matrix
Hydrated Silica (SiO2·nH2O)
Petrified Wood
Silicified Wood (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartzite with Quartz Crystal Vug
Metamorphic Quartzite (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Tumbled blue-gray stone beads, likely labradorite or dyed quartz
Probable labradorite (plagioclase feldspar; approximately NaAlSi₃O₈–CaAl₂Si₂O₈), though exact identification requires testing
Geode fragment, likely quartz-lined basalt or chalcedony nodule
Microcrystalline quartz (SiO₂), possibly with iron-oxide staining in a basaltic host
Black obsidian (probable)
Volcanic glass; primarily SiO₂-rich rhyolitic composition
Metallic sulfide ore, likely pyrite-bearing rock
Pyrite (FeS₂), possibly with chalcopyrite and quartz/host rock
Green glass-like cabochon, likely synthetic glass or resin
Unidentified green transparent material; possibly molded glass, synthetic spinel, or resin
Rough Black Diamond (Bort / Carbonado)
Diamond (C)
Rough Diamond
Diamond (pure Carbon, C)
Quartz (Smoky/Rock Crystal)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
Quartz Vein in Sandstone
Hydrothermal Quartz (SiO2) in Arenite
Diamond (in a jewelry setting)
Cubic Carbon (C)
Diamond (set in a gold ring)
Carbon (C) - Adamantine cubic carbon
Diamond
Diamond (C)
Polished/tumbled quartz-rich pegmatite
Quartz–feldspar pegmatite, with iron-oxide staining; chiefly SiO₂ and KAlSi₃O₈–NaAlSi₃O₈
Pink-and-white quartz-rich rock, likely rose quartz matrix
Quartz (SiO₂), possibly intergrown with feldspar or chalcedony
Tumbled white quartz or quartzite pebble
Quartz (SiO₂), possibly massive quartzite
Rounded gray pebble, likely basalt or andesite
Fine-grained volcanic rock, probably basaltic-andesite; exact identification requires testing