Organic Gemstone (Not A Rock Or Mineral)

Grey Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Quartz (Milky/Common)

Quartz (Silicon Dioxide, SiO2)

Grey Agate (Tumbled)

Silicon Dioxide (SiO2)

Desert Rose (Baryte or Gypsum Rose)

Baryte (BaSO4) or Gypsum (CaSO4·2H2O)

Blue Chalcedony

Microcrystalline Quartz (SiO2)

Granite

Phaneritic Igneous Rock (Granite)

Quartz with Mica inclusions (Pegmatite)

Silicon Dioxide (SiO2) with Muscovite/Biotite inclusions

Peridot

Olivine ((Mg,Fe)2SiO4)

Vesicular Basalt with Xenocrysts

Mafic Igneous Plutonic/Extrusive Complex

Dendritic Opal

Opalized Chalcedony with Manganese Inclusions (SiO2 · nH2O)

Indigo Gabbro

Gabbro (MaFIC intrusive rock)

Quartz (Smoky/Grey variety)

Silicon Dioxide (SiO2)

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Citrine (Yellow Quartz)

Silicon Dioxide (SiO2)

Sodalite

Sodalite (Na8(Al6Si6O24)Cl2)

Carnelian

Carnelian (a variety of Chalcedony) - SiO2

Green Quartz (Prasiolite/Adventurine/Jasper)

Silicon Dioxide (SiO2)

Sapphirine in Matrix

Sapphirine (Mg,Al)8(Al,Si)6O20

Amazonite

KAlSi3O8 (Potassium Aluminum Silicate)

Sugilite

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

Amazonite

Amazonite (KAlSi3O8, a triclinic variety of Potassium Feldspar)

Kunzite (variety of Spodumene)

Lithium Aluminum Silicate (LiAlSi2O6)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Amazonite

Potassium Feldspar (KAlSi3O8)

Garnet (Almandine variety)

Almandine Garnet (Fe3Al2(SiO4)3)

Amazonite (with smoky quartz/red jasper inclusions)

Tectosilicate - Microcline Feldspar (KAlSi3O8)

Beryl (likely var. Aquamarine or Goshenite) in Matrix

Beryllium Aluminum Silicate (Be3Al2Si6O18)

Amethyst

Amethyst (SiO2 - Silicon Dioxide with iron impurities)

Herkimer Diamond (Quartz)

Silicon Dioxide (SiO2)

Tiffany Stone

Fluorite Opal (a complex mix of Fluorite, Opal, Calcite, Dolomite, Quartz, and Bertrandite)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Sedimentary rock with quartz veining

Laminated siltstone or mudstone with hydrothermal quartz veins

Rose Quartz

Silicon dioxide with traces of titanium, iron, or manganese (SiO2)

Tiger's Eye

Pseudomorph of quartz after crocidolite (SiO2 with iron inclusions)

Herkimer Diamond (Quartz Crystal)

Silicon Dioxide (SiO2)

Limonite Concretion (Ironstone)

Limonite / Goethite (FeO(OH)·nH2O)

Biotite (Black Mica)

Biotite - K(Mg,Fe)3(AlSi3O10)(OH)2

Dragon Blood Jasper

Epidote with Pietersite or Red Jasper (Ca2Al2Fe3+[Si2O7][SiO4]O(OH))

Schist

Schist (various mineralogical compositions including mica, chlorite, talc, etc.)

Sandstone

Arenite (predominantly SiO2)

Chert (Flint Pebbles)

Microcrystalline or Cryptocrystalline Quartz (SiO2)