Organic (Non Geological)

Nephrite Jade

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Pink Granite

Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)

Quartzite

Quartzite (primarily SiO2)

Rough Quartz in Pegmatite Matrix

Quartz (Silicon Dioxide - SiO2) in Granitic Pegmatite

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Quartz (Clear / Rock Crystal)

Silicon Dioxide (SiO2)

Sandstone (Ferruginous)

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Sandstone (likely Quartzose type)

Clastic sedimentary rock (primarily SiO2)

Sandstone (Ferruginous)

Ferruginous Sandstone (SiO2 with Fe2O3)

Sandstone

Arenite (composed primarily of SiO2)

Grey Banded Agate

Chalcedony (Silicon Dioxide, SiO2)

Quartz on Schist

Silicon Dioxide (SiO2) on Foliated Metamorphic Rock

Greenstone

Metamorphosed Mafic Igneous Rock

Carnelian

Carnelian (Silica, SiO2)

Sandstone (Quartzose Sandstone)

Arenite (SiO2 principal component)

Aventurine (Green)

Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)

Coquina

Bioclastic Limestone

Blue Sapphire

Corundum (Al2O3)

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Jasper Breccia

Silicon Dioxide (SiO2) - Brecciated Microcrystalline Quartz

Polygenetic Breccia

Clastic Breccia (containing lithic fragments in a fine-grained matrix)

Quartzite with Chert inclusions

Metamorphosed Quartz-rich Rock (SiO2)

Quartz (Iron-Stained)

Silicon Dioxide (SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Jasper

Jasper (Silicon Dioxide, SiO2)

Granite (Pink/Red variety)

Phaneritic Felsic Intrusive Igneous Rock (composed primarily of Quartz, K-Feldspar, and Plagioclase)

Unakite (Tumbled)

Unakite (altered granite)

Agate

Silicon Dioxide (SiO2) - Cryptocrystalline Chalcedony

Yellow Quartz / Quartzite Pebble

Silicon Dioxide (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Yellow Quartzite (River Pebble)

Quartzite (primarily SiO2)

Pink Dyed Agate

Silicon Dioxide (SiO2) with synthetic pigment

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2 - Silicon Dioxide)

Quartz with Mica inclusions (likely Schist or Gneiss host)

Silicon Dioxide (SiO2) with Phyllosilicates (KAl2(AlSi3O10)(OH)2)

Cloud Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Sandstone with Bedding Planes

Arenite (Sedimentary rock composed primarily of sand-sized minerals)

Moqui Marble (Shaman Stone)

Iron Oxide Concretion (Hematite/Goethite-encased Sandstone)

Tiger's Eye (Rough)

Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)

Quartz (Milky/Clear)

Silicon Dioxide (SiO2)

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 staining)

Obsidian

Volcanic Glass (SiO2 - Silicon Dioxide with impurities)