Antropogenic (Man Made Glass Byproduct)

Rounded quartz-rich pebble

Chert or quartzite pebble (tentative; mostly microcrystalline quartz, SiO₂)

Weathered quartz-rich rock, possibly chert or milky quartz

Mostly microcrystalline or crystalline quartz (SiO₂), identification uncertain from photograph

Quartz (likely a clear or rock crystal variety)

Quartz (SiO2 - Silicon Dioxide)

Pearl (Biogenic Mineraloid)

Calcium carbonate (Aragonite) and Conchiolin, CaCO3

Coquina / Fossiliferous Limestone

Fossiliferous Limestone (Calcite, CaCO3)

Rhodonite

Rhodonite (MnSiO3)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Granodiorite with Quartz Veining

Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins

Fluorite

Fluorite (Calcium Fluoride - CaF2)

Polished serpentine pendulum

Serpentine-group minerals, chiefly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄

Quartz (River-worn Pebble)

Quartz (SiO2)

Diamond

Carbon (C)

Pyrite

Iron Disulfide (FeS2)

Clear Quartz (or Rock Crystal)

Quartz (SiO₂)

Rough Diamond

Diamond (Pure Carbon: C)

Rounded pink granite pebble

Granite, a coarse-grained felsic intrusive igneous rock composed primarily of quartz, feldspar, and minor mica or amphibole

Quartz (variety of colors)

SiO2 (Silicon Dioxide)

Quartzite

Quartzite (SiO2)

Quartzite (River Pebble)

Metamorphosed Quartz Sandstone (SiO2)

Mica schist (possibly garnet–mica schist)

Muscovite–biotite schist; chiefly quartz, feldspar, muscovite, and biotite

Quartz (likely Milky Quartz or Chalcedony)

Quartz (SiO2 - Silicon Dioxide)

Aquamarine and clear quartz

Aquamarine (Be3Al2Si6O18), Quartz (SiO2)

Tumbled quartz-rich pebble

Microcrystalline quartz (SiO₂), possibly weathered chert or chalcedony

Diamond

Carbon (C)

Quartz

SiO₂ (Silicon Dioxide)

Diamond

Diamond (pure Carbon, C)

Green fluorite (likely)

Fluorite — calcium fluoride, CaF₂

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Mica-rich schist

Muscovite–biotite schist, commonly quartz-bearing

Quartz (in matrix)

Quartz (SiO₂)

Sandstone

Quartz Arenite (a common type of sandstone, given the appearance), Arkose, Greywacke (depending on mineralogy)

Chert (or Flint)

Chert (cryptocrystalline quartz), SiO2

Quartz (possibly milky quartz or quartz with inclusions)

SiO2 (Silicon Dioxide)

Tumbled green aventurine (probable)

Quartz aggregate, SiO₂, commonly containing fuchsite mica inclusions

Diamond

Carbon (C)

Diamond

Carbon (C)

Weathered quartz-rich rock, possibly chert or quartzite fragment

Indeterminate; likely microcrystalline quartz (SiO₂), possibly with iron-oxide staining

Tumbled yellow quartz (likely citrine or iron-stained quartz)

Quartz, SiO₂; yellow color from trace iron or irradiation/heat-related coloration

Sandstone (Ferruginous)

Arenite (SiO2 with Fe2O3 inclusions)

Polished pink quartzite or jasper

Quartzite, predominantly SiO₂; possibly iron-stained jasper/chalcedony

Coal (Anthracite / Bituminous)

Organic Sedimentary Rock (Carbon-based)

Leopard Skin Jasper

Silicified Rhyolite or Orbicular Jasper (SiO2)