Sedimentary Rock Or Mineral (Depending On Origin And Purity)

Quartzite

Quartzite (primarily SiO2)

Sandstone (likely a river or beach pebble)

Sandstone (a clastic sedimentary rock)

Banded Sedimentary Rock

Sedimentary rock with Liesegang banding

Sandstone with Iron Staining

Arenite (SiO2 based with Fe2O3 staining)

White Jade

Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (NaAlSi2O6)

Sandstone

Arenite (composed primarily of SiO2, or Silicon Dioxide)

Weathered graywacke or sandstone fragment

Lithic sandstone, likely quartz–feldspar–rock-fragment aggregate

Fluorite Geode

Calcium Fluoride (CaF2)

Quartz

Silicon Dioxide (SiO2)

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in Geode form

Granite Pebble

Granite (a phaneritic intrusive igneous rock consisting of quartz, alkali feldspar, and plagioclase)

Quartz Vein in Host Rock (Likely Slate or Shale)

Hydrothermal Quartz (SiO2) in Pelitic host rock

Likely mica schist

Mica-rich schist, probably biotite–quartz–feldspar schist

Pebble

Lithic fragment / Sedimentary clast

Quartzite

Metamorphosed Sandstone (Mainly SiO2)

Flint or chert

Microcrystalline quartz (SiO₂), commonly with chalcedony and minor impurities

Sandstone (with Feldspathic/Arkose qualities)

Arenite (primarily SiO2 with KAlSi3O8 components)

Sandstone (Banded)

Clastic sedimentary rock (primarily SiO2)

Weathered quartz-bearing rock, possibly calcite vein fragment

Indeterminate; likely quartz (SiO₂) with carbonate minerals such as calcite (CaCO₃)

Banded gneiss

Gneiss, likely quartz–feldspar–mica gneiss

Pearl

Nacre (primarily aragonite, CaCO₃, in an organic conchiolin matrix)

Banded Gneiss (River Cobble)

Gneiss (a high-grade metamorphic rock)

White Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone

Arenite (composed primarily of Quartz: SiO2)

Fluorite

Calcium Fluoride (CaF2)

Quartz Geode

Silicon Dioxide (SiO2)

Sandstone

Sedimentary Rock (Quartz/Feldspar grains cemented together)

Gastropod Fossil

Class Gastropoda (fossilized)

Ruby

Corundum (Al2O3)

Iron-rich rock fragment (likely hematite/goethite-rich ironstone)

Ironstone, composed chiefly of iron oxides/hydroxides such as hematite (Fe₂O₃) and goethite (FeO(OH)); exact identification requires testing

Blue-gray chalcedony (likely common quartz/chert)

Microcrystalline quartz, SiO₂; possibly weathered chert or chalcedony

Quartz pebble

Silicon Dioxide (SiO2)

Sandstone

Clastic Sedimentary Rock

Gastropod Fossil (Steinkern)

Class Gastropoda (internal mold)

Sandstone (Fossiliferous)

Arenite / Clastic Sedimentary Rock

Purple cabochon gemstone, likely amethyst or purple sapphire/spinel

Indeterminate from image; possible quartz (SiO₂), corundum (Al₂O₃), or spinel (MgAl₂O₄)

Diamond (set in jewelry)

Diamond (Carbon, C)

Chalcedony in Limestone Host Rock

Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)

Blue-green gemstone ring, likely treated turquoise or synthetic/treated beryl

Indeterminate from image; possibilities include turquoise (CuAl6(PO4)4(OH)8·4H2O), apatite, or treated beryl

Fragmented Sedimentary Pebble

Clastic Sedimentary Specimen

Banded gneiss

Gneiss; typically quartz–feldspar–biotite ± amphibole

Diamond

Carbon (C)