Flagstone (Sandstone)
Clastic Sedimentary Rock (composed of quartz and feldspar)
sedimentary
Category
Synthetic Polymer (Synthetic Material)
Browse synthetic polymer (synthetic material) specimens identified by the Rock Identifier community.
Coquina or Fossiliferous Limestone
Fossiliferous Calcarenite (CaCO3)
sedimentary
Quartzite Pebble
Quartzite (SiO2 with minor impurities)
metamorphic
Fired Clay Brick (Anthropic Rock substitute)
Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)
metamorphic (man-made / anthropic)
Concrete Fragment
Hardened Portland Cement Composite
Anthropogenic (Man-made material mimicking sedimentary rock)
Chert (often called Flint or River Pebble)
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Chert (Flint)
Chert (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Granite (Dioritic variant)
Granite (Phaneritic Igneous Rock)
igneous
Chert (Yellow Jasper/Quartzite Pebble)
Microcrystalline Silicon Dioxide (SiO2)
sedimentary
Nephrite Jade
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2)
metamorphic
Chert (variations include Flint/Jasper)
Chert (SiO2)
sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Yellow/Tan variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Granite Pebble
Granite (composed primarily of Quartz, Feldspar, and Mica)
igneous
Granite Sand (Decomposed Granite)
Grus / Quartz-Feldspar Detritus
sedimentary
Chert (variations include Flint/Jasper)
Cryptocrystalline Silicon Dioxide (SiO2)
sedimentary
Quartzite Pebble
Metamorphic Quartz (SiO2)
metamorphic
Chert (Red/Pink Jasper subtype)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Chert (SiO2)
sedimentary
Chert (often called Flint)
Microcrystalline to cryptocrystalline quartz (SiO2)
sedimentary
Lava Rock with Fabric Impression
Scoria or Basalt with anthropogenic impressions
igneous
Polished Ocean Jasper
Orbicular Jasper (variety of Chalcedony/Quartz, SiO2)
mineral
Limonite (Yellow Ochre)
FeO(OH)·nH2O (Hydrous iron(III) oxide-hydroxide mixture)
Mineral (Iron Ore)
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
sedimentary
Petrified Wood
Silicon Dioxide (SiO2) - Calcified / Silicified Wood
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
mineral
Chert (often called Flint in this context)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Slag
Ferrous Slag (Siliceous industrial waste)
Anthropogenic (Man-made industrial byproduct)
Limonite (Iron Stone/Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
mineral
Cupronickel (on a 1981 Mexico 20 Pesos coin)
Copper-Nickel Alloy (Cu75Ni25)
mineral
Mother of Pearl and Onyx
Aragonite (Mother of Pearl) and Chalcedony (Onyx)
mineral
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (with Lichen)
Arenite (composed primarily of SiO2)
sedimentary
Sandstone (Ferruginous)
Arenite (Fe-rich)
sedimentary
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Sandstone (Yellow/Siltstone variant)
Arenite (SiO2 primarily)
sedimentary
Chert (Jasper/Common Opal mix)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (with Limonite staining)
Arenite (primarily SiO2 with FeO(OH)·nH2O)
sedimentary
Quartz (Milky or Druzy Quartz)
Silicon Dioxide (SiO2)
mineral
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary