Dark-colored Igneous Rock (likely Basalt or Diabase)
Basalt (extrusive igneous) or Diabase (intrusive igneous)
Igneous Rock
Category
Mineral, Possibly Rock Fragment Containing A Mineral
Browse mineral, possibly rock fragment containing a mineral specimens identified by the Rock Identifier community.
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Granodiorite
Granodiorite (containing Quartz, Plagioclase Feldspar, Biotite, and Hornblende)
igneous
Sandstone (Greywacke/Siltstone variant)
Clastic Sedimentary Rock (Lithic Wacke)
sedimentary
Quartz on Sandstone
Silicon Dioxide (SiO2) in Lithic Sandstone
sedimentary
Sandstone (Quartzite-rich Cobble)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Lapis Lazuli
Lazurite-dominant Metamorphic Rock (complex aluminosilicate)
metamorphic
Limonite with Opal infusion
FeO(OH)·nH2O (Limonite) / SiO2·nH2O (Opal)
mineral
Limestone (Brecciated/Recrystallized)
Calcium Carbonate (CaCO3)
sedimentary
Quartz Geode (partially formed/chalcedony with iron staining)
Quartz (SiO2) with Chalcedony (cryptocrystalline quartz) and likely Iron Oxides/Hydroxides
Mineral/Sedimentary Rock Feature
Sandstone (River Pebble)
Arenite (primarily SiO2)
sedimentary
Quartz
Silicon Dioxide (SiO2)
Mineral
Quartz (Rock Crystal) with minor impurities
Quartz (SiO2)
Mineral
Sandstone Cobble
Arenite (Secondary classification based on grain size)
sedimentary
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Mineral or Sedimentary Rock (with mineral inclusions)
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Amygdaloidal Rhyolite
Amygdaloidal felsic extrusive rock
igneous
Chipped Glass/Plastic Fragment
Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic
Man-made material (simulant/artifact)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide staining/cementing)
sedimentary
Pebble (likely Sandstone or Granitic Pebble)
Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)
Rock (likely Sedimentary)
Sandstone (likely Graywacke or Lithic Sandstone)
Arenite / Wacke (SiO2 based with lithic fragments)
sedimentary
Quartz Druzy (on Matrix)
Silicon Dioxide (SiO2)
mineral
Schist
Mica Schist (primarily consisting of muscovite KAl2(AlSi3O10)(OH)2 or biotite K(Mg,Fe)3(AlSi3O10)(OH)2)
metamorphic
Amygdaloidal Basalt
Basalt with secondary amygdule minerals (likely Epidote or Chlorite)
igneous
Sandstone (likely Quartzose Sandstone with mineral staining)
Arenite (composed mainly of SiO2)
sedimentary
Garnetiferous Pegmatite
Pegmatite with Almandine Garnet and Muscovite
igneous
Lapis Lazuli
Lapis Lazuli (Primary mineral: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)
metamorphic
Amygdaloidal Basalt
Amygdaloidal Basalt
igneous
Sandstone (specifically Arkose or Ferruginous Sandstone)
Sandstone (SiO2 with iron oxide inclusions)
sedimentary
Smoky Quartz
Smoky Quartz (SiO2: Silicon Dioxide)
mineral
Sandstone (Ferruginous)
Arenite (SiO2 with Iron Oxide impurities)
sedimentary
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
sedimentary
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)
Quartz (SiO₂)
Mineral
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
igneous
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
sedimentary
Bauxite
Bauxite (principal ore of aluminum, primarily Al(OH)3)
sedimentary
Shale
Shale (Lutite)
sedimentary
Note: Item is not a geological specimen
n/a
none
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
sedimentary