Organic Gemstone (Often Associated With Sedimentary Sequences)

Quartz Crystal with Inclusions

Silicon Dioxide (SiO2)

Granite

Granite (felsic intrusive igneous rock)

igneous

Blue Sapphire

Corundum (Al2O3 - Aluminum Oxide with Iron and Titanium impurities)

Sandstone

Arenite (Siliclastic Sedimentary Rock)

Sugilite

Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)

Rhodonite

Rhodonite (Manganese Iron Magnesium Calcium Silicate) - (Mn+2,Fe+2,Mg,Ca)SiO3

Red Jasper

Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)

Red Jasper

Silicon Dioxide (SiO2)

Sunstone

Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)

Quartzite

Quartzite (primarily SiO2)

metamorphic

Chrysocolla

Hydrated copper silicates (Cu, Al)2H2Si2O5(OH)4·nH2O

Clear Quartz (Tumbled)

Silicon Dioxide (SiO2)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Precious Opal

Hydrated amorphous silica (SiO2·nH2O)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartzite

Quartzite (primarily SiO2)

Metamorphic

Fossiliferous Limestone

Limestone (composed primarily of calcite with included fossils CaCO3)

Sedimentary

Black Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Red Garnet

Pyrope or Almandine (Silicate group, X3Y2(SiO4)3)

Sodalite

Na8(Al6Si6O24)Cl2

Smoky Quartz Cluster

Quartz (Silicon Dioxide) - SiO2

Epidote (likely Unakite component or Epidosite)

Epidote (Ca2(Al2Fe)(SiO4)(Si2O7)O(OH))

metamorphic

Chert (Flint variety)

Silicon Dioxide (SiO2)

Angelite

Anhydrite (Calcium Sulfate, CaSO4)

Green Tourmaline (Verdelite)

Elbaite (Complex Borosilicate: Na(Li,Al)3Al6(BO3)3Si6O18(OH)4)

Granite

Granite (a felsic intrusive igneous rock)

Igneous Rock

Celestite (Celestine)

Strontium sulfate (SrSO4)

Amethyst Quartz

Silicon Dioxide (SiO2) with iron impurities

Sunstone (Feldspar)

Plagioclase Feldspar ((Ca, Na)(Al, Si)4O8)

Emerald

Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities

Quartzite Pebble

Quartzite (SiO2)

metamorphic

Tourmaline (Multi-colored)

Complex Borosilicate (Na,Ca)(Li,Mg,Al,Fe)3Al6(BO3)3Si6O18(OH)4

Amazonite

K(AlSi3O8) - Microcline

Amazonite

Microcline (Amazonstone), K(AlSi3O8)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Agate (Chalcedony)

Agate (Silicon Dioxide - SiO2)

Clear Quartz

Silicon Dioxide (SiO2)

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Carnelian

Carnelian (Varietal of Chalcedony, SiO2 with Iron Oxide impurities)

Green Aventurine

Aventurine (a variety of Quartz, SiO2)

Corundum

Corundum (Al2O3)