Sedimentary (Artificial)

Blue Lace Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Polished blue lace agate slice

Chalcedony (microcrystalline quartz), SiO₂, commonly with blue-gray banding and a druzy quartz center

Pink Banded Agate (Dyed)

Chalcedony (cryptocrystalline silica), chemical formula SiO2

Aura Quartz (Coated Quartz)

Silicon Dioxide (SiO2) treated with metallic vapor

Red sandstone pebble

Quartz-rich sandstone, commonly ferruginous sandstone (SiO₂-dominated)

Asphalt aggregate (crushed stone in bitumen)

Artificial composite; predominantly crushed granite, basalt, limestone, and/or recycled aggregate bound by bitumen

Dyed mineral cluster, likely calcite or aragonite

Calcite (CaCO₃) or aragonite (CaCO₃), artificially color-enhanced

Dyed agate geode slice

Banded chalcedony (microcrystalline SiO₂), commonly sold as a dyed agate slice

Blue aventurine quartz (likely dyed or tumbled quartzite)

Quartz, silicon dioxide (SiO₂), with blue coloration from inclusions or dye

Red chalcedony (likely dyed or heat-treated)

Microcrystalline quartz, SiO₂; possibly red agate/carnelian

Red Tiger's Eye

Pseudomorph of Macrocrystalline Quartz after Crocidolite (SiO2)

Dyed agate slice

Microcrystalline quartz (SiO₂), typically banded chalcedony

Dyed tumbled quartz (likely quartzite or quartz crystal)

Quartz, silicon dioxide (SiO₂)

Dyed tumbled stone, likely chalcedony or quartz

Microcrystalline quartz (SiO₂), probably dyed magenta

Dyed Agate

Silicon Dioxide (SiO2) - Variety Agate / Chalcedony

Lemon Quartz

Silicon dioxide (SiO2) with iron inclusions

Blue Obsidian

Volcanic Glass (Silica, SiO2)

Blue Quartzite (Dyed Quartzite)

Quartzite (SiO2 with dye enhancements)

Vesicular volcanic scoria (likely weathered basaltic scoria)

Scoria; chiefly vesicular basalt, composed mainly of plagioclase, pyroxene, and iron-rich glass

Hag Stone (Quartz Pebble with Natural Hole)

Quartz (Silicon Dioxide - SiO2)

Iron Meteorite

Iron-Nickel Alloy (Kamacite and Taenite)

Dyed Agate

SiO2 (Silicon Dioxide)

Pink granite (likely weathered)

Granite; predominantly quartz, potassium feldspar, plagioclase, and mica

Rose Quartz and Milky Quartz

Silicon Dioxide (SiO2)

Yellow quartz-bearing rock, possibly sulfur-stained quartz or calcite

Indeterminate; likely quartz (SiO₂) and/or calcite (CaCO₃) with yellow iron/sulfur staining

Polished black stone, possibly basalt or black obsidian

Likely fine-grained basalt (plagioclase and pyroxene) or volcanic glass (obsidian; rhyolitic composition)

Blue Topaz

Aluminum silicate fluoride hydroxide [Al2SiO4(F,OH)2]

Dyed Alum or Dyed Quartz (Ornamental Crystal)

Silicon Dioxide (SiO2) or Potassium Alum [KAl(SO4)2·12H2O]

Red Chalcedony (likely dyed)

Chalcedony (a variety of Quartz), SiO2

Polished blue obsidian with a pale mineral crust

Obsidian (volcanic glass), likely coated or encrusted with quartz/calcite

Dyed Blue Agate

Silicon Dioxide (SiO2) with artificial cobalt-based dye

Painted River Rock (likely Quartzite or Granite)

Quartzite or Granitic Gneiss (painted)

Aura Quartz Geode (Angel Aura Quartz)

Silicon Dioxide (SiO2) bonded with precious metals

Blue Obsidian (Cullet Glass)

Silicon Dioxide (Amorphous Glass)

Native American Hammerstone / Pitted Stone

Modified lithic artifact (often quartzite, basalt, or granite)

Iridescent polished/tumbled stone (likely coated quartz or glassy synthetic material)

Indeterminate; possibly quartz (SiO₂) with an artificial iridescent coating

Peacock ore (likely chalcopyrite-bornite specimens)

Iridescent chalcopyrite, CuFeS₂, commonly altered to bornite, Cu₅FeS₄

Dyed blue banded agate (tumbled)

Microcrystalline quartz, SiO₂ (chalcedony variety)

Tumbled chalcedony (likely carnelian or common agate)

Microcrystalline quartz, SiO₂; chalcedony variety

Blue chalcedony (likely dyed or coated)

Chalcedony, microcrystalline quartz (SiO₂)

Tumbled blue stone, likely blue aventurine or dyed chalcedony

Aventurine quartz (SiO₂) or chalcedony (microcrystalline SiO₂); exact identification requires testing

Tumbled blue chalcedony (likely blue quartz)

Chalcedony, cryptocrystalline SiO₂; possibly chrysoprase or dyed quartz