Limestone
Sedimentary Calcium Carbonate (CaCO3)
Category
Browse igneous rock specimens identified by the Rock Identifier community.
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone (Fossiliferous)
Clastic Sedimentary Rock (primarily SiO2)
Unakite
Epidotized Granite
Sandstone
Sandstone (Clastic Sedimentary Rock)
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
Chert (Jasper variation)
Silicon dioxide (SiO2)
Concrete Rubble with Aggregate
Hardened Portland Cement Paste with Coarse Aggregate
Jasper
Silicon dioxide (SiO2)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Fire Opal (Common/Precious in Matrix)
Hydrated Silica (SiO2·nH2O)
Sandstone Concretion
Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)
Ferruginous Quartz
Quartz with Iron Oxide inclusions (SiO2 + Fe2O3)
Glacial Erratic (Sandstone/Quartzite)
Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)
Conglomerate
Conglomeratic Sandstone
Grass (Organic Matter/Soil)
Poaceae (family of monocotyledonous flowering plants)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Garnet-Bearing Schist
Almandine Garnet Micaceous Schist
Chert / Flint
Microcrystalline Quartz (SiO2)
Grey Agate (Tumbled)
Silicon Dioxide (SiO2)
Chert (often called Flint in dark varieties)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Chert (Cryptocrystalline Silica, SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Desert Rose (Baryte or Gypsum Rose)
Baryte (BaSO4) or Gypsum (CaSO4·2H2O)
Conglomerate
Conglomerate (Clastic sedimentary rock)
Sandstone with Liesegang Rings
Arenite with Iron Oxide Concretions
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Quartz Geode (partially formed/chalcedony with iron staining)
Quartz (SiO2) with Chalcedony (cryptocrystalline quartz) and likely Iron Oxides/Hydroxides
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Olivine (Peridot)
Magnesium Iron Silicate (Mg,Fe)2SiO4
Cloudy Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz Vein (Iron-stained)
Silicon Dioxide (SiO2) with limonite/hematite staining
Sodalite
Sodalite, Na8(Al6Si6O24)Cl2
Conglomerate
Clastic sedimentary rock (Conglomerate)
Red Shale
Fissile Siliciclastic Sedimentary Rock
Sandstone (Greywacke/Siltstone variant)
Arenite / Wacke (SiO2 with diverse mineral inclusions)