Sedimentary Rock (Technically A Variety Of Chalcedony)

Snowflake Obsidian

Volcanic Glass with Cristobalite inclusions

Kambaba Jasper (Crocodile Jasper)

Stromatolite (Fossilized Algae within Microcrystalline Quartz), SiO2

Chrysocolla in Quartz (Gem Silica)

Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / SiO2 (Quartz)

Brown Antique Granite

Anorthosite (Technically a plutonic rock composed mainly of plagioclase feldspar)

Chert Nodule

Chert (Cryptocrystalline variety of Quartz, SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Pink Dyed Agate (Pink Agate Slice)

Silicon Dioxide (SiO2) - Chalcedony / Cryptocrystalline Quartz

Thunderegg (Agate-filled Geode Node)

Silicon dioxide (SiO2) with various inclusions

Agate (specifically, likely a geode slice or nodule)

Agate (a variety of Chalcedony, with chemical formula SiO2)

Chert (Flint/Jasper variety)

Microcrystalline Quartz (SiO2)

Chert (Nodule)

Silicon Dioxide (SiO2)

Jasper (yellow/cream variety)

SiO₂ (Cryptocrystalline Quartz)

Blue Dyed Agate

Silicon Dioxide (SiO2) with artificial pigment

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Turquoise (Green variety)

Hydrous phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Pebble (river rock/beach pebble)

Pebble (clast size class)

Conglomerate

Conglomerate (clastic sedimentary rock type)

Chert (White-Tan variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Jasper/Chalcedony)

Microcrystalline Quartz (SiO2)

Onyx

Chalcedony (SiO2) with parallel banding

Conglomerate

Conglomerate (Detrital sedimentary rock)

Agate (Lace Agate Geode Slice)

Silicon Dioxide (SiO2)

Travertine (Tufa)

Chemical Sedimentary Limestone (CaCO3)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Conglomerate

Conglomerate (Clastic sedimentary rock)

Orca Agate

Chalcedony (SiO2) with various inclusions

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Conglomerate

Conglomerate (Detrital Sedimentary Rock)

Chert (specifically Tan/Yellow Chert)

Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)

Amygdaloidal Rhyolite (often called Lake Superior Agate relative)

Rhyolite with Calcite/Quartz amygdules (SiO2 and secondary minerals)

Obsidian

Obsidian (Volcanic Glass)

Obsidian

Volcanic Glass (SiO2 + minor impurities)

Grey Chalcedony (Tumbled Moon)

Microcrystalline Quartz (SiO2)

Chert Pebble (with Quartz Vein)

Chert (Cryptocrystalline Silica - SiO2)

Blue Quartz

Quartz (SiO2) with inclusions

Sandstone (Wonderstone)

Arenite (composed primarily of SiO2 with Fe2O3 impurities)

Chert Pebble/Nodule

Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)

Chert (often called Flint in dark varieties)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Turritella Agate (Elimia Agate)

Silicified Elimia tenera (formerly misidentified as Turritella)

Ferruginous Sandstone

Clastic sedimentary rock (SiO2 with Fe2O3/FeO(OH) cement)

Mixed Tumbled Gemstones and River Rocks

Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)

Sandstone (Micaceous)

Arenite (primarily SiO2 with Phyllosilicates)