River/Stream Pebble
Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)
Category
Browse mineral (extraterrestrial) specimens identified by the Rock Identifier community.
River/Stream Pebble
Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)
Schist
Schist (various compositions)
Sandstone
Sandstone (Silicon Dioxide, SiO2)
Red Sandstone
Arenite with iron oxide (Hematite) cement
Sandstone with Iron Oxide Staining
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Red Sandstone
Clastic sedimentary rock (primarily SiO2 with Fe2O3)
Malachite
Copper carbonate hydroxide Cu2CO3(OH)2
Sandstone (Ferruginous)
Arenite (Fe-rich)
Black Marble
Recrystallized Calcite (CaCO3)
Turquoise (Blue Howlite / Magnesite imitation)
CuAl6(PO4)4(OH)8·4H2O (for natural Turquoise); Ca2B5SiO9(OH)5 (for Howlite)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 oxides)
Red Sandstone
Arenite (with Iron Oxide)
Sandstone (Red Sandstone)
Clastic Sedimentary Rock (primarily SiO2 with Iron Oxide)
Garnet (Almandine/Pyrope series)
Silicate mineral (Almandine: Fe3Al2Si3O12; Pyrope: Mg3Al2Si3O12)
Chrysocolla in Matrix
Hydrated copper silicate - (Cu,Al)2H2Si2O5(OH)4·nH2O
Sandstone (likely Quartzose Sandstone)
Arenite (composed primarily of SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Peacock Ore (Bornite or Chalcopyrite)
Bornite (Cu₅FeS₄) or iridescent Chalcopyrite (CuFeS₂)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Milky Quartz with Chlorite/Epidote inclusions
Silicon Dioxide (SiO2) with phyllosilicate/sorosilicate inclusions
Quartz-bearing Ore (likely Gold-bearing Quartz)
Quartz (SiO2) with potential sulfide mineralization (Pyrite/Arsenopyrite)
Copper Ore (with Malachite and Azurite)
Hydroxide copper carbonate (Cu2CO3(OH)2 / Cu3(CO3)2(OH)2)
Quartz with mica and feldspar (Pegmatite fragment)
Granitic Pegmatite (composed mainly of SiO2 with KAlSi3O8)
Garnet
Almandine Garnet (Fe3Al2(SiO4)3)
Milky Quartz with inclusions
Quartz (Silicon Dioxide, SiO2)
Pyrite and Fluorite on Quartz (Matrix Specimen)
Iron Disulfide (FeS2) and Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)
Fluorite (Purple variety)
Calcium Fluoride (CaF2)
Fossil Coral
Fossilized Scleractinia or Tabulata (various genera/species)
Fossilized Shark Tooth
Fossilized elasmobranch tooth (Apatite/Calcium Phosphate)
Metallic Ornament / Jewelry
N/A - This is an artificial object, not a geological specimen.
Fossilized Dinosaur Skull (Tyrannosaurus rex)
Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica
Limestone
Calcium Carbonate (CaCO3)
Dinosaur Fossil (Tyrannosaurus rex skull replica/specimen)
Tyrannosaurus rex (fossilized in permineralized sedimentary matrix)
Azurite-Malachite (often called Azerite Malachite or Azurmalachite)
Azurite (Cu3(CO3)2(OH)2) and Malachite (Cu2CO3(OH)2)
Olivine (Peridot when gem-quality)
Olivine Group (Magnesium Iron Silicate, (Mg,Fe)2SiO4)
Glacial Cobbles (predominantly Granite and Gneiss)
Mixed lithologies (Quartz, Feldspar, Mica assemblage)
Schist
Schist
Fluorite
Calcium Fluoride (CaF2)
Quartz with Chalcopyrite
Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)