Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Category
Sedimentary Rock (Specifically A Clastic Sedimentary Rock Formed Into A Cobble)
Browse sedimentary rock (specifically a clastic sedimentary rock formed into a cobble) specimens identified by the Rock Identifier community.
Quartz Pebble (Geode-like)
Silicon Dioxide (SiO2)
Mineral
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Diorite (Salt and Pepper Rock)
Diorite
igneous
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Pyrite (Iron Pyrites)
Iron Sulfide (FeS2)
mineral
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
sedimentary
Quartz / Rock Crystal
Silicon Dioxide (SiO2)
mineral
Garnet (specifically Almandine)
Almandine (Fe3Al2(SiO4)3)
mineral
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Limonite streaks)
sedimentary
Bauxite
Bauxite (Al2O3·2H2O)
sedimentary
Ferruginous Sandstone (Grit)
Clastic Sedimentary (Ironstone-rich Sandstone)
sedimentary
N/A - Image does not contain a rock or mineral
Anthropogenic textile material
Non-geological
Clear Quartz Cluster
Silicon Dioxide (SiO2)
mineral
Dalmatian Stone (often called Dalmatian Jasper)
Peralkaline Quartz-Feldspar Rock with Arfvedsonite (formerly believed to be Jasper)
igneous
Fossilized Bone Fragment
Permineralized Vertebrate Bone (Hydrox yapatite replaced by Silica or Calcite)
sedimentary
Quartz (Milky/Crystal Variety)
Silicon Dioxide (SiO2)
mineral
Schist (Micaceous Schist)
Schist (comprising Muscovite/Biotite mica, Quartz, and Feldspar)
metamorphic
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Brown Antique Granite
Anorthosite (Technically a plutonic rock composed mainly of plagioclase feldspar)
igneous
Ocean Jasper
Silicon dioxide with impurities (SiO2 + impurities)
sedimentary
Petrified Wood
Silicified Wood (primarily Quartz / Chalcedony: SiO2)
metamorphic
Red Jasper (possibly banded)
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Jasper with Quartz Veining
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Chert Nodule
Chert (Cryptocrystalline variety of Quartz, SiO2)
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Bauxite
Bauxite (Al2O3·nH2O)
sedimentary
Red Jasper (Chert)
Silicon dioxide (SiO2) with iron oxide inclusions
sedimentary
Shale
Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Chert (Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Quartzite Pebble (River Rock)
Quartzite (mainly SiO2)
metamorphic
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
mineral
Green Aventurine
Silicon Dioxide (Quartz variety) with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)
metamorphic
Black Opal
Hydrated Silica (SiO2·nH2O)
mineral
Quartz (likely Clear Quartz or Rock Crystal)
Quartz (SiO2)
Mineral
Yellow Quartzite or Yellow Jasper
Quartzite (primarily SiO2 with Iron oxide staining)
metamorphic
Quartz
Quartz (SiO2 - Silicon Dioxide)
Mineral