Pyrite
Iron Sulfide (FeS2)
Category
Browse sedimentary (or mineraloid) specimens identified by the Rock Identifier community.
Pyrite
Iron Sulfide (FeS2)
General Rock and Mineral Collection (Center: Angelite / Blue Anhydrite)
Anhydrite (Calcium Sulfate, CaSO4)
Weathered sandstone
Quartz-rich sandstone, likely ferruginous subarkose
Weathered sandstone or siltstone cobble
Clastic sedimentary rock, probably quartz-rich sandstone; exact identification requires testing
Weathered shale or mudstone
Clastic mudrock, chiefly clay minerals, quartz, and feldspar
Polished fossil-bearing shale or mudstone
Fossiliferous carbonaceous mudstone/shale; visible fossils may be bivalves or ammonites, but species cannot be confirmed from the image
Banded sandstone pebble
Quartz-rich sandstone, likely iron-oxide- and organic/mineral-stained; exact variety uncertain
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
Shale with Iron Staining
Fissile Mudrock (Sedimentary Rock)
Shale (with Iron Staining)
Argillaceous mudstone / Shale
Sandstone (Ferruginous)
Arenite (Fe-oxide cemented)
Sandstone (River Cobble / Pebble)
Sedimentary Rock (Quartz Sandstone / Arenite)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Iron Oxide cement)
Shale
Fissile Mudstone
Sandstone (Ferruginous)
Clastic Sedimentary Rock (SiO2 with Fe2O3/FeOOH cement)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Banded gneiss
Gneiss, likely quartz–feldspar–mica gneiss
Weathered Sandstone Cobble
Arenite / Quartz Sandstone
Seashell (Calcium Carbonate)
Calcium Carbonate (CaCO3)
Fossil Belemnite Guard
Belemnitella spp. (rostrum)
Weathered sandstone fragment
Quartz-rich sandstone (compositionally uncertain)
Rounded sandstone or quartz-rich sedimentary pebble
Likely quartz arenite/subarkose; exact identification requires testing
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various additives
Banded gneiss
Foliated gneiss, likely quartz–feldspar–biotite or amphibole gneiss
Small pale stone, possibly quartz or limestone
Indeterminate from image; likely quartz (SiO₂) or calcite-rich limestone (CaCO₃)
Chert / Flint Arrowheads
Cryptocrystalline Quartz (SiO2)
Pyrite
Iron Disulfide (FeS2)
Mixed Tumbled Gemstones (Agate, Aventurine, Pyrite, etc.)
Multiple (principally Silicon Dioxide SiO2 and Iron Disulfide FeS2)
Jasper
Silicon dioxide (Microcrystalline Quartz, SiO2)
Sandstone
Sedimentary rock composed mainly of quartz sand
Fossiliferous Sandstone / Fossil Fragment
Fossiliferous Sedimentary Matrix with Indeterminate Fossil Material
Polished brown river pebble (likely chert or fine-grained sandstone)
Indeterminate; probable microcrystalline quartz (chert) or quartz-rich sandstone
Orange Calcite
Calcium Carbonate (CaCO3)
Pyrite
Iron Sulfide (FeS2)
Celestine (Celestite)
Strontium sulfate (SrSO4)
Halite (Rock Salt)
Halite (Sodium Chloride, NaCl)
Fossil oyster shell
Oyster (family Ostreidae), preserved as calcite/aragonite shell
Fossil gastropod shell
Fossilized gastropod, likely a small marine snail; exact genus cannot be determined from the image
Quartz-veined Sandstone Pebble
Quartzose Sandstone with Quartz Veinlets
Weathered iron-rich sandstone or ferruginous siltstone
Clastic sedimentary rock, likely quartz-rich sandstone cemented by iron oxides (Fe₂O₃/Fe₃O₄)
Banded Sandstone (River Pebble)
Arenite (SiO2 primarily)