Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
Category
Browse sedimentary specimens identified by the Rock Identifier community.
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
Weathered sandstone
Quartz-rich sandstone, likely ferruginous subarkose
Pitted Sedimentary Rock / Cupstone
Sedimentary rock with weathering pit (arenite / sandstone)
Banded gneiss
Gneiss, likely quartz–feldspar–mica gneiss
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)
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)
Weathered sandstone fragment
Quartz-rich sandstone (compositionally uncertain)
Rounded sandstone or quartz-rich sedimentary pebble
Likely quartz arenite/subarkose; exact identification requires testing
Small pale stone, possibly quartz or limestone
Indeterminate from image; likely quartz (SiO₂) or calcite-rich limestone (CaCO₃)
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
Banded gneiss
Foliated gneiss, likely quartz–feldspar–biotite or amphibole gneiss
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)
Weathered Sandstone Cobble
Arenite / Quartz Sandstone
Seashell (Calcium Carbonate)
Calcium Carbonate (CaCO3)
Fossil Belemnite Guard
Belemnitella spp. (rostrum)
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)
Calcite
Calcium Carbonate (CaCO3)
Fossil-bearing rock, possibly with a fossilized shell or coralline specimen
Indeterminate fossil in sedimentary matrix; precise identification is not possible from the image
Sandstone Pebble
Sandstone (primarily Quartz, SiO2)
Fossil gastropod shell
Fossilized gastropod, likely a small marine snail; exact genus cannot be determined from the image
Shale
Shale (clastic sedimentary rock)
Shale with Trace Fossils
Fissile mudrock (Shale)
Sandstone
Arenite
Shale
Shale (Lutite)
Shale
Fissile mudstone (rich in clay minerals and quartz)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)