Granodiorite (River Rock / Cobble)
Granodiorite; Phaneritic intrusive igneous rock dominated by plagioclase, quartz, and hornblende/biotite
igneous
Category
Anthropogenic (Man Made Artifact)
Browse anthropogenic (man made artifact) specimens identified by the Rock Identifier community.
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Quartzite (River Cobble)
Metamorphic Rock (composed predominantly of SiO2)
metamorphic
Chert (varietal: Flint/River Pebble)
Cryptocrystalline Quartz (SiO2)
sedimentary
Yellow Chalcedony (Carnelian/Yellow Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Mineral
Greywacke with Quartz Veins
Lithic Sandstone (Greywacke) with SiO2 inclusions
sedimentary
Chert (Chert Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Slate
Foliated Metamorphic Rock (primarily composed of quartz, illite, and chlorite)
metamorphic
Granite Cobble
Phaneritic Felsic Igneous Rock (Granite)
igneous
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (primarily SiO2)
sedimentary
Basalt River Stone
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Anthracite Coal
Anthracite (Carbon)
metamorphic
Pumice
Vesicular volcanic glass
igneous
Cherry Creek Jasper (also known as Red Creek Jasper or Cherry Creek Agate)
Jasper, microcrystalline quartz (SiO₂)
Sedimentary Rock
Citrine Quartz
Quartz (SiO2) - specifically, a variety of macrocrystalline quartz
Mineral
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
mineral
Amber (Simulated/Faturan Style)
Resin mix (Likely Phenolic/Celluloid if synthetic, Succinite if natural)
Organic Gemstone (not a mineral)
Peridot
Olivine ((Mg, Fe)2SiO4)
mineral
Pearl
Calcium carbonate (CaCO3) - Aragonite/Calcite variety
mineral
Portable Ceramic Space Heater
Polished Acrylonitrile Butadiene Styrene (ABS) Plastic with Ceramic Heating Elements
not a rock (synthetic/industrial object)
Diamond (in a jewelry setting)
Cubic Carbon (C)
mineral
Rhodonite
Manganese silicate (MnSiO3)
mineral
Rhodonite
Rhodonite (Mn,Fe,Mg,Ca)SiO3
mineral
River/Stream Pebble
Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)
Mineral, specifically a rock fragment
Limonite
Limonite (Hydrous iron oxides, predominantly Goethite FeO(OH)·nH2O)
mineral
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary (microcrystalline quartz)
Anthracite
Anthracite Coal (C)
sedimentary
Stromatolite
Stromatolite (Cyanobacteria-formed Organo-sedimentary structure)
sedimentary
Quartz (Yellow/Citrine variety)
Crystalline Silicon Dioxide (SiO2)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Quartzite Pebble (with iron staining)
Quartzite (SiO2 with ferric oxide impurities)
metamorphic
Rhodonite
Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3
mineral
Spessartine Garnet
Manganese aluminum silicate (Mn2+3Al2(SiO4)3)
mineral
Plastic Building Toy (Lego-style piece)
Acrylonitrile Butadiene Styrene (ABS)
not a rock/mineral
Digital Multimeter (Synthetic Object)
Digital Multimeter (DMM)
not a rock
Pearl
Calcium carbonate (CaCO3) as Aragonite or Calcite
mineral
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Organic Mineraloid
Rhodonite
Rhodonite (Manganese Iron Magnesium Calcium Silicate - (Mn,Fe,Mg,Ca)SiO3)
mineral
Aquamarine with Sunstone
Aquamarine (Be3Al2Si6O18), Sunstone (Na,Ca)Al(Si,Al)Si2O8
Mineral