Likely weathered gray stone or chert fragment
Uncertain; possibly microcrystalline quartz (SiO₂)-rich chert
Category
Browse sedimentary (man made composite) specimens identified by the Rock Identifier community.
Likely weathered gray stone or chert fragment
Uncertain; possibly microcrystalline quartz (SiO₂)-rich chert
Quartzite and Sandstone Pebbles
Silicon dioxide (SiO2)
Tumbled Agate
Silicon Dioxide (SiO2)
Crinoid Marble (Fossilized Limestone)
Crinoidal Limestone (comprising Calcite/Aragonite CaCO3)
Sandstone (Quartz-rich)
Arenite (primarily SiO2)
Limestone
Sedimentary rock composed mainly of calcite (CaCO3)
Limestone
Sedimentary rock composed mainly of calcite (CaCO3)
Limestone
Sedimentary rock primarily composed of Calcite (CaCO3)
Conglomerate
Clastic sedimentary rock (composed mostly of SiO2)
Sandstone
Clastic Sedimentary Rock (composed mostly of SiO2)
Sandstone (Gneissic or Banded)
Clastic Sedimentary Rock (composed predominantly of SiO2)
Flagstone (Sandstone)
Clastic Sedimentary Rock (composed of quartz and feldspar)
Banded Iron Formation (BIF) / Banded Sandstone Nodule
Hematite-rich Sandstone / Ferruginous Chert
Sand
Siliciclastic sediment / Quartz sand (SiO2)
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone
Arenite
Blue Celestite
Strontium Sulfate (SrSO4)
Sandstone
Arenite
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Iron Oxide staining)
Chert / Flint
Silicon dioxide (SiO2)
Blue Calcite
Calcite (Calcium Carbonate, CaCO3)
Sandstone
Sandstone (clastic sedimentary rock), primarily SiO2
Limestone with Calcite Crust
Sedimentary Calcium Carbonate (CaCO3)
Limestone River Pebble
Sedimentary Calcium Carbonate (CaCO3)
Sandstone (Ferruginous / River-worn Cobble)
Sandstone (SiO2 with iron oxide impurities)
Red Sandstone
Sedimentary Arenite / Quartzose Sandstone
Geode (unopened)
Silica-filled Concretion (SiO2)
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Limestone Riprap
Sedimentary Calcium Carbonate (CaCO3)
Limestone Pebble
Sedimentary Calcium Carbonate (CaCO3)
Sandstone (Banded)
Clastic Sedimentary Rock: Arenite
Limestone
Sedimentary Calcium Carbonate (CaCO3)
Quartz-bearing granite or granitic pegmatite
Felsic intrusive rock, chiefly quartz (SiO₂), feldspar, and minor mica
Chalcedony
SiO2 (Silicon Dioxide)
Red Sandstone (Iron-rich)
Ferruginous Sandstone (variable formula, primarily SiO2 + Fe2O3)
Banded calcite (likely marble or calcite-rich limestone)
Calcite, CaCO₃; possibly calcitic marble
Limonite
FeO(OH)·nH2O (Hydrated iron oxide)
Weathered sandstone
Quartz-rich clastic sandstone, likely iron-oxide-stained
Sandstone
Arenite (composed primarily of SiO2)