Sedimentary (Artificial)

Carnelian Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Dyed Agate

Chalcedony (SiO2 with impurities)

Tumbled coral limestone

Biogenic calcarenite/coral limestone, predominantly calcium carbonate (CaCO₃; calcite/aragonite)

Dragon Vein Agate (Dyed/Fractured Quartz)

Silicon dioxide (SiO2)

Dyed Blue Agate

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Banded Agate (Dyed Purple)

Agate (Variety of Chalcedony/Quartz), SiO2

Dyed Agate Slice

Chalcedony (Silicon Dioxide, SiO2) with artificial pigment

Dyed Crackle Quartz (Green)

Quenching-treated Quartz (Silicon Dioxide, SiO2)

Dragon Vein Agate (Dyed/Treated)

Agate (SiO2)

Purple Dyed Agate Geode (Banded Chalcedony)

Silicon Dioxide (SiO2) - variety: Agate

Rainbow Hematite (Titanium-Coated Hematite)

Titanium-treated Hematite (Fe2O3)

Tumbled yellow calcite

Calcite (CaCO₃), likely honey/yellow calcite

Likely black beach pebble

Undetermined; possibly basalt, chert, or dark slate

Tumbled blue-green chalcedony (likely dyed agate or chrysoprase)

Microcrystalline quartz, SiO₂; chalcedony/agate variety

Copper-bearing rock, likely bornite/chalcopyrite in iron-rich matrix

Chalcopyrite (CuFeS₂) and/or bornite (Cu₅FeS₄) in limonite/goethite matrix

Smoky Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Dyed pink stone, likely rhodonite or dyed howlite/magnesite

Rhodonite: MnSiO₃; possible howlite: Ca₂B₅SiO₉(OH)₅

Green cabochon gemstone, likely aventurine or dyed chalcedony

Indeterminate from image; possible quartz variety (SiO₂), including aventurine quartz or chalcedony

Drill Core Sample

Cylindrical Rock Core (Specific mineralogy varies by extraction site)

Blue quartz (likely tumbled dyed or coated quartz)

Quartz, silicon dioxide (SiO₂)

Blue-dyed howlite beads (likely)

Howlite, Ca₂B₅SiO₉(OH)₅, commonly dyed blue to imitate turquoise

Dyed Agate

SiO2 (Chalcedony/Agate)

Uncertain fine-grained rock or mineral-bearing specimen

Indeterminate; possible quartz- or feldspar-bearing matrix with reflective grains

Druzy chalcedony pendant, likely coated or dyed

Microcrystalline quartz (SiO₂), chalcedony with druzy quartz; surface may have titanium or metallic coating

Dyed Pink Quartzite

Tumbled and Dyed Quartzite (SiO2 with dye treatment)

Clear Quartz (Milky Quartz pebble)

Silicon Dioxide (SiO2)

Cobalt Blue Slag Glass

Amorphous Silicon Dioxide (anthropogenic) with Cobalt additives

Concrete or asphalt-like aggregate surface with a dark fragment

Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock

Carnelian (a variety of Chalcedony)

Cryptocrystalline Quartz (SiO2) with iron oxide inclusions

Mixed mineral specimens, prominently chalcopyrite and amethyst

Chalcopyrite (CuFeS₂) with secondary copper minerals; amethyst, purple quartz (SiO₂)

Polished carnelian (likely)

Carnelian, orange-red chalcedony; microcrystalline quartz (SiO₂)

Agate (Dyed High-Grade Polished Slice)

Silicon dioxide (SiO2), Chalcedony crystal variety

Blue Agate (Dyed)

Silicon Dioxide (Chalcedony), SiO2

Pink Dyed Agate (Banded Chalcedony)

Silicon dioxide (SiO2) - variety Chalcedony

Dyed Crackle Quartz

Silicon Dioxide (SiO2) with synthetic dye

Dyed Agate

SiO2

Tumbled chalcedony or quartz pebble

Microcrystalline quartz, SiO₂ (likely chalcedony); exact identification is uncertain from the image

Dyed Blue Agate

Chalcedony (Silicon Dioxide / SiO2)

Blue Quartzite (Dyed Quartzite)

Silicon Dioxide (SiO2) with dye

Green obsidian (likely molded or heat-treated glass-like specimen)

Volcanic glass; predominantly rhyolitic composition (silica-rich amorphous SiO₂)

Banded Slag Glass (Leland Blue/Frankfort Green style)

Anthropogenic Glass Specimen (Amorphous Silicon Dioxide with impurities)