Amethyst (Agate/Chalcedony variety)
Silicon Dioxide (SiO2) with iron impurities
Category
Browse igneous rock specimens identified by the Rock Identifier community.
Amethyst (Agate/Chalcedony variety)
Silicon Dioxide (SiO2) with iron impurities
Sandstone Concretion
Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)
Unakite
Epidotized Granite
Chert (specifically Jasper)
Silicon dioxide (SiO2) with iron oxide inclusions
Sandstone
Arenite (primarily SiO2)
Amethyst
Silicon Dioxide with trace Iron (SiO2)
Quartz (Iron-stained or Ferruginous)
Silicon Dioxide (SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Ferruginous Sandstone
Ferruginous Clastic Sedimentary Rock
Sandstone (Ferruginous)
Sandstone (mainly SiO2 with Fe2O3 staining)
Sandstone (Pebble)
Arenite (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Milky and Smoky variety)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Carnelian
Carnelian (SiO2)
Sandstone
Arenite (SiO2 principal)
Sandstone
Arenite (Sedimentary rock composed of sand-sized minerals or rock grains)
Limestone
Calcareous Sedimentary Rock (CaCO3)
Diorite (River Cobble)
Intrusive Igneous Diorite
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Hypersthene
Hypersthene (Magnesium Iron Silicate - (Mg,Fe)SiO3)
Pyrite
Iron Sulfide (FeS2)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Sodalite
Na8(Al6Si6O24)Cl2
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
Sandstone
Clastic Sedimentary Rock (composed mostly of SiO2)
Turquoise
Turquoise (Hydrated phosphate of copper and aluminium) CuAl6(PO4)4(OH)8·4H2O
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Fossiliferous Limestone
Fossiliferous Calclutite / Bio-calcarenite (CaCO3)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within a metamorphic matrix
Chert / Jasper
Microcrystalline Quartz (SiO2)
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (primarily Quartz, SiO2)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Chert (specifically a weathered Chert nodule or fragment)
Chert; Microcrystalline or Cryptocrystalline Quartz (SiO2)
Banded Chert (River Stone)
Silicon Dioxide (SiO2)
Jasper-Agate Conglomerate (Potentially Puddingstone)
Jasper-cemented Silicate Aggregate (SiO2)