Sandstone
Arenite
sedimentary
Category
Not A Rock (Man Made Origin)
Browse not a rock (man made origin) specimens identified by the Rock Identifier community.
Quartzite
Quartzite (composed mainly of SiO2)
metamorphic
Crazy Lace Agate
Silicon Dioxide (SiO2) with iron and aluminum inclusions
sedimentary mineral
Granite
Phaneritic Intrusive Igneous Rock (Granite)
igneous
Basalt with Quartz Vein and Weathering Crust
Amygdaloidal or Porphyritic Basalt
igneous
River Stone (Basalt Porphyry)
Porphyritic Basalt
igneous
Basalt
Basalt (primarily composed of Plagioclase feldspar and Pyroxene)
igneous
Basalt River Pebble
Basalt (Mafic Extrusive Volcanic Rock)
igneous
Basalt with Iron Oxidation
Aphanitic Mafic Igneous Rock (composed primarily of Plagioclase and Pyroxene)
igneous
Granite
Phaneritic Plutonic Felsic Rock (K-Feldspar + Quartz + Plagioclase)
igneous
Basalt (Vesicular)
Basalt (Mafic Extrusive Igneous Rock)
igneous
Vesicular Basalt
Extrusive Mafic Igneous Rock (composed of Plagioclase feldspar, Pyroxene, and Olivine)
igneous
Basalt
Mafic volcanic rock (Primary minerals: Plagioclase feldspar, Pyroxene)
igneous
Granite
Phaneritic plutonic rock (SiO2 range 70-75%)
igneous
Chert (varietal: Jasper or Flint)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
sedimentary
Sandstone Concretion (Omar or Nut Rock)
Sedimentary Concretion (specifically an 'Omarolluk' or Omar)
sedimentary
Shale
Fissile Mudstone (primarily composed of clay minerals and quartz)
sedimentary
Silty Shale
Silty Shale (Fissile Sedimentary Rock)
sedimentary
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
sedimentary
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Conglomerate with Native Copper
Clastic Sedimentary Rock with Native Copper (Cu)
sedimentary
Ferruginous Sandstone (Ironstone)
Sedimentary rock with high iron oxide content (Fe2O3 / FeO(OH))
sedimentary
River Stone (likely Siltstone or fine-grained Basalt)
Clastic Sedimentary (Siltstone) or Mafic Igneous (Basalt)
sedimentary or igneous
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Unakite
Epidotized Granite
metamorphic
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Sedimentary/Metamorphic Matrix
Metamorphic or Igneous (context dependent)
Quartz-veined Sedimentary Rock
Hydrothermally veined Clastic Sedimentary Rock (SiO2 veins in Matrix)
sedimentary
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone (with possibly iron oxides and other minerals)
Sandstone
Sedimentary rock
Oolitic Chert
Ooidal Microcrystalline Quartz (SiO2)
sedimentary
Quartzite
Quartzite (primarily SiO2)
metamorphic
Granodiorite
Granodiorite (Intermediate to Felsic Intrusive Rock)
igneous
Limonitic Iron Ore / Goethite
Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
igneous
Gold
Native Gold (Au)
Mineral
Iolite-bearing Gneiss (Cordierite)
Cordierite (Mg2Al4Si5O18) in Gneiss matrix
metamorphic
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Fossil Coral
Scleractinia (fossilized calcium carbonate)
sedimentary
Amethyst
Amethyst (Silicon Dioxide, SiO2)
mineral
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
sedimentary
Emerald in Matrix
Beryl (Be3Al2Si6O18) containing Chromium/Vanadium impurities
mineral