Sedimentary (Man Made)

Sandstone (Ferruginous)

Sandstone (mainly SiO2 with Fe2O3 staining)

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily SiO2)

Sandstone

Arenite (primarily Quartz Arenite)

Sandstone (likely River-tumbled Picture Sandstone)

Arenite (predominantly SiO2 with iron oxide impurities)

Quartzite and Sandstone Pebbles

Silicon dioxide (SiO2)

Sandstone

Arenite

Sandstone (Ferruginous)

Arenite (Fe2O3 enriched)

Brown Sandstone

Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)

Limestone

Calcium Carbonate (CaCO3)

Sandstone

Arenite (primarily SiO2)

Sandstone (Ferruginous)

Arenite (with Iron Oxide cement)

Limestone (Flagstone)

Fossiliferous Limestone (CaCO3)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 inclusions)

Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)

Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.

Mixed Gemstone Beaded Jewelry

Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)

Obsidian

Obsidian (volcanic glass, amorphous silica rich rock)

Weathered quartz-rich metamorphic rock

Likely quartzite or quartz-rich gneiss; exact identification requires a fresh surface and testing

Likely quartz-rich metamorphic rock (quartzite or quartz-veined schist)

Quartzite/siliceous schist; chiefly quartz (SiO₂), with probable mica and iron-oxide staining

Weathered quartz-rich stone, possibly chalcedony or calcite

Likely microcrystalline quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Red Sandstone (Iron-Rich)

Arenite (Fe2O3)

Sandstone

Arenite (primarily SiO2 with various cementing agents)

Sandstone (likely Graywacke or Lithic Sandstone)

Arenite / Wacke (SiO2 based with lithic fragments)

Sandstone (with Limonite staining)

Arenite (FeOx-rich)

Sandstone (Banded)

Clastic Sedimentary Rock (composed of SiO2, CaCO3, or Fe2O3 cement)

Limestone

Sedimentary Calcite (CaCO3)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cementation)

Limestone

Calcium Carbonate (CaCO3)

Sandstone

Arenite

Fossiliferous Limestone

Calcite (CaCO3) Rich Bio-sedimentary Rock

Sandstone (River Cobble)

Arenite

Sandstone (Quartzose)

Arenite (primarily SiO2)

Limestone (with Iron-Oxide staining)

Sedimentary Calcium Carbonate (CaCO3)

Quartz (Milky Quartz)

Quartz (SiO2 - Silicon Dioxide)

Blue calcite (probable)

Calcite, calcium carbonate (CaCO₃)

Weathered sandstone or iron-stained sedimentary rock

Likely quartz-rich sandstone; exact identification is uncertain from the photograph

Iron-stained sandstone or weathered ironstone

Ferruginous sandstone; chiefly quartz (SiO₂) cemented or coated by iron oxides such as hematite (Fe₂O₃) and goethite (FeO(OH))

Polished dark pebble, possibly basalt or chert

Uncertain; likely fine-grained basalt (plagioclase–pyroxene) or microcrystalline silica (chert)

Possible iron-rich chert or slag-like rock

Microcrystalline quartz (SiO₂), possibly iron-stained chert; exact identification is uncertain from the image

Caliche (also known as hardpan, calcrete, kankar)

Primarily composed of calcium carbonate (CaCO₃), often mixed with other minerals like quartz, clay minerals, and iron oxides.

Banded Sandstone

Clastic Sedimentary Sandstone