River Rock (likely Siltstone or fine-grained Sandstone)
Clastic Sedimentary Rock
Category
Browse igneous rock specimens identified by the Rock Identifier community.
River Rock (likely Siltstone or fine-grained Sandstone)
Clastic Sedimentary Rock
Quartz Geode
Silicon Dioxide (SiO2)
Sandstone (likely Arkosic)
Clastic Sedimentary Rock
Shale or Siltstone
Sedimentary Rock (Siliciclastic)
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
Conglomerate
Polymictic Conglomerate
Druzy Quartz on Sandstone
Silicon Dioxide (SiO2) with Quartz crystals
Chalcedony in Limestone Host Rock
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Pyrite in Shale
Iron Sulfide (FeS2)
Desert Rose
Gypsum (variety Selenite) - CaSO4·2H2O
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Concretion
Various mineral compositions, typically carbonate or iron oxide cemented sediment
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Jasper (Yellow Jasper)
Silicon Dioxide (SiO2) with iron inclusions
River Rock (Greywacke/Siltstone)
Siltstone / Argillaceous Greywacke
Sandstone (Quartzite texture)
Arenite (SiO2 secondary)
Jasper (Iron-rich)
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) impurities
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)
Quartz
Silicon Dioxide (SiO₂)
Turquoise
Turquoise (Hydrated copper aluminum phosphate, CuAl6(PO4)4(OH)8·4H2O)
Unakite
Unakite (altered granitic rock)
Sandstone Concretion
Sedimentary concretion
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Unakite
Epidotized Granite
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst Quartz Druse
Silicon Dioxide (SiO2) with iron impurities
Quartz
Quartz (SiO2 - Silicon Dioxide)
Amethyst
Amethyst (SiO2 with Iron impurities)
Slate
Slate (foliated metamorphic rock)
Quartz Geode (Cracked Open)
Quartz (Silicon Dioxide - SiO2)
Magnetite / Hematite mix (Iron Ore)
Fe3O4 (Magnetite) / Fe2O3 (Hematite)
Magnetite (Lodestone)
Magnetite (Fe3O4)
Schist
Schist (various mineral compositions)
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
Sandstone (lithic/greywacke variant)
Clastic sedimentary rock (primarily SiO2 with rock fragments)
Quartz (Druzy)
Silicon Dioxide (SiO2)
Fossil Bivalve Shell
Class Bivalvia (e.g., Veneriidae family)
Milky Quartz
Silicon Dioxide (SiO2)
Unakite
Epidotized Granite
Lapis Lazuli (Low Grade)
Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2)