Sedimentary Or Igneous (Host Environment)

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone with Desert Varnish

Arenite (SiO2 predominantly) with Ferromanganese coating

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Quartz-veined altered rock

Likely quartz-bearing metasediment or altered igneous rock; vein mineral: quartz (SiO₂)

Likely mica-rich schist (possibly phyllite)

Muscovite–biotite schist; exact identification requires examination of a fresh surface

Brown Agate

Silicon Dioxide (SiO2)

Jasper with Quartz inclusions

Silicon Dioxide (SiO2) with varying mineral impurities

Smoky Quartz with Chert

Silicon Dioxide (SiO2)

Rounded gray sandstone or siltstone cobble

Lithified quartz–feldspar–clay sediment; exact petrographic identification requires testing

Weathered quartz-bearing rock, possibly calcite vein fragment

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

Quartz (partially iron-stained)

Silicon Dioxide (SiO2)

Gneiss

Metamorphic Gneiss (High-grade regional metamorphism)

Geode

Quartz / Chalcedony nodule

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Quartz

Silicon Dioxide (SiO2)

Quartz fragment

Quartz (silicon dioxide, SiO₂)

Mica-rich schist

Mica schist, likely muscovite–biotite schist with quartz

Quartz

Silicon Dioxide (SiO2)

Quartz

Silicon Dioxide (SiO2)

Weathered quartz-rich metamorphic rock, likely gneiss or quartzite

Quartz–feldspar–mica metamorphic rock; exact identification is uncertain from the photograph

Quartz with inclusions

SiO2

Unidentified gray-brown stone

Likely fine-grained quartz–feldspar rock; exact identification is not possible from this close, blurred image

Quartz vein in host rock

Quartz (SiO₂), likely milky quartz; host rock is uncertain from the photo

Quartz Geode

Silicon Dioxide (SiO2)

Epidote-bearing Rock / Epidote Inclusion

Epidote (Ca2(Al, Fe)3(SiO4)3(OH)) in host rock

Rounded river pebble, likely quartz-rich sandstone or weathered igneous rock

Indeterminate; possibly quartzite, sandstone, or fine-grained granitic rock

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Geode

Quartz / Chalcedony nodule

Quartz

Silicon Dioxide (SiO2)

White Quartz

Silicon Dioxide (SiO2)

Quartz vein fragment

Milky quartz (SiO₂), possibly with weathered host rock

Fossilized Shell or Coral Fragment in Matrix

Invertebrate Fossil in Sedimentary Rock

Gneiss (with Garnet)

Gneiss (Feldspar-Quartz-Biotite-Garnet Metamorphic Rock)

Quartz

Silicon Dioxide (SiO2)

Banded quartz-rich metamorphic rock (likely quartzite or quartz-mica schist)

Quartzite/schist composed chiefly of SiO₂ quartz with mica, feldspar, and iron-oxide or copper-colored accessory minerals

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Red Agate

Chalcedony (SiO2)

Quartz (Druzy/Macro-crystalline)

Silicon Dioxide (SiO2)

Polished garnet-bearing gneiss

Biotite-quartz-feldspar gneiss with almandine garnet (garnet: Fe₃Al₂(SiO₄)₃)

Quartz Pebble

Silicon Dioxide (SiO2)

Chalcedony (Agate/Carnelian)

Cryptocrystalline Quartz (SiO2)

Concrete

Anthropogenic Conglomerate