Industrial Byproduct (Anthropogenic Material)

Quartz

Silicon Dioxide (SiO2)

Quartz Pebble with Chlorite or Epidote Inclusions

Silicon Dioxide (SiO2) with inclusions

Mica Schist

Schist

Sandstone

Sedimentary Rock (Quartz arenite/Arkose)

Jasper

Silicon Dioxide (Microcrystalline Quartz, SiO2)

Quartz pebble

Silicon dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone

Sedimentary Clastic Rock

Crinoid Stem Fossil

Crinoida (columnal ossicles)

Quartz Pebble

Silicon Dioxide (SiO2)

Sandstone (Calcareous)

Clastic sedimentary rock (primarily SiO2 with CaCO3 cement)

Unakite

Unakite (metamorphosed granitic rock)

Fossiliferous Sandstone with Plant Remains

Arenite with Carbonaceous impressions (likely Paleozoic/Mesozoic Flora)

Coarse-grained Granite

Granitoid (Felsic Plutonic Rock)

Sandstone

Arenite (SiO2 with various cementing agents)

Pink Granite

Phaneritic Plutonic Igneous Rock (high K-feldspar)

Porphyritic Rhyolite (Birdseye Rhyolite)

Rhyolite (Porphyritic texture)

Sandstone

Arenite (SiO2 based)

Sandstone (Pebble)

Arenite (SiO2 based)

Granite

Granite

Quartzite Geode or Crystalline Quartz Node

Silicon Dioxide (SiO2)

Opalite

Synthetic Glass (typically Silica/Magnesium based with metal additives)

Blue Goldstone

Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)

Polished ocean jasper (orbicular jasper)

Microcrystalline quartz (SiO₂) with chalcedony, iron oxides, and assorted silicate inclusions

Weathered gray-green pebble

Indeterminate; possibly altered basalt, serpentinite, or a greenish metamorphic rock

Small rounded pebble

Unidentified lithic clast; likely fine-grained sandstone, mudstone, or basalt

Blue faceted gemstones, likely blue sapphire

Corundum (Al₂O₃), blue varieties colored chiefly by iron and titanium

Polished ocean jasper (orbicular jasper), likely

Silica-rich microcrystalline quartz/chalcedony aggregate, commonly with feldspar, epidote, and iron oxides; composition varies

Polished banded agate (likely sardonyx)

Cryptocrystalline chalcedony, SiO₂; reddish bands are iron-stained layers

Agate

Silicon dioxide (Chalcedony), SiO2

Agate

Silicon Dioxide (Chalcedony), SiO2

Muscovite Schist

Metamorphic rock primarily composed of quartz and muscovite mica

Tumbled sodalite (probable)

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂; possibly blue-dyed jasper or lapis lazuli

Quartz Geode

Silicon Dioxide (SiO2)

Yellow Sapphire

Corundum (Al2O3 with trace amounts of iron)

Aquamarine

Beryl (Be3Al2(SiO3)6)

Black Tourmaline

Schorl (NaFe2+3Al6(Si6O18)(BO3)3(OH)4)

Carved quartz skull

Quartz (silicon dioxide, SiO₂)

Black Tourmaline

Schorl (NaFe3Al6(Si6O18)(BO3)3(OH,F)4)

Pegmatite or Graphic Granite

Intrusive Igneous Rock

Orange Calcite

Calcium Carbonate (CaCO3)

Almandine Garnet

Fe3Al2(SiO4)3