Sedimentary (If Natural Jasper) Or Artificial (If Slag)

Blue Agate (Dyed)

Silicon Dioxide (Chalcedony), SiO2

Tumbled quartz-rich pebble

Likely quartz-bearing chert or jasper; primarily microcrystalline SiO₂

Tumbled agate/chalcedony pebble

Microcrystalline quartz (SiO₂), likely brown/banded agate or jasper

Blue Onyx (Dyed Agate/Chalky Chalcedony)

Silicon Dioxide (SiO2) with artificial pigment

Copper slag or vesicular basalt with copper minerals

Industrial slag / Basaltic matrix with secondary copper minerals

Dyed Agate

Silicon Dioxide (SiO2)

Polished dark stone, likely basalt

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, with possible olivine and magnetite

Druzy chalcedony pendant, likely coated or dyed

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

Green agate/geode slab

Cryptocrystalline quartz (chalcedony), SiO₂, likely agate with druzy quartz

Carnelian Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Possible flint (chert) fragment

Microcrystalline quartz (SiO₂), commonly called flint when dark and nodular

Iron-rich laterite or weathered ironstone

Goethite–hematite-bearing ferruginous duricrust; commonly approximated as FeO(OH) and Fe₂O₃

Dyed Agate

Silicon Dioxide (SiO2) - Variety Agate / Chalcedony

Dyed Agate

SiO2 (Chalcedony/Agate)

Citrine

Silicon Dioxide (SiO2)

Quartz (Citrine variety)

Silicon Dioxide (SiO2)

Iridescent bismuth crystal

Bismuth (Bi), commonly laboratory-grown and oxide-coated

Likely jasper or iron-rich chert

Microcrystalline quartz (SiO₂), commonly colored by iron oxides

Turquoise

Turquoise (Hydrated phosphate of copper and aluminium), CuAl6(PO4)4(OH)8·4H2O

Polished vesicular basalt (likely iron-rich volcanic rock)

Basalt, predominantly plagioclase–pyroxene–olivine; surface may include iron-oxide minerals or metallic-looking infill

Likely slag or metallic industrial byproduct

Unidentified iron-rich ferrous slag; possibly magnetite-bearing slag

Red coral (likely precious coral)

Corallium sp.; calcium-carbonate skeleton, primarily calcite

Clear Quartz (Milky Quartz pebble)

Silicon Dioxide (SiO2)

Polished black stone, likely black jasper or basalt

Most likely microcrystalline quartz (black jasper/chert), SiO₂; basalt is a plausible alternative

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Weathered brown iron-rich pebble

Likely ferruginous sandstone or ironstone; exact identification requires testing

Tumbled smoky quartz (probable)

Quartz, SiO₂; smoky variety colored by irradiation-related defects

Banded Agate (Dyed Purple)

Agate (Variety of Chalcedony/Quartz), SiO2

Blue slag glass / industrial smelter slag

Man-made iron-rich silicate slag; composition variable, commonly Fe–Ca–Mg–Al silicates with glassy phases

Dyed Quartzite (Pink/Magenta)

Silicon Dioxide (SiO2) - Artificially Colored Quartzite

Blue Topaz

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

Dark basalt or industrial slag (tentative)

Basalt; predominantly plagioclase and pyroxene, possibly with olivine

Blue Aura Quartz

Silicon Dioxide (SiO2) with metallic vapor coating

Likely weathered iron-rich rock or slag fragment

Indeterminate; possibly limonite/goethite-bearing rock (FeO(OH)·nH₂O) or industrial iron slag

Yellow Agate

SiO2 (Quartz variety)

Smoky quartz (likely)

Quartz, silicon dioxide (SiO₂), naturally irradiated variety

Dyed tumbled quartz (likely quartzite or quartz crystal)

Quartz, silicon dioxide (SiO₂)

Dyed agate slice

Microcrystalline quartz (SiO₂), typically banded chalcedony

Slag Glass / Industrial Slag

Anthropogenic Glass

Possible hematite-rich ironstone or magnetite-bearing specimen

Likely hematite (Fe₂O₃), magnetite (Fe₃O₄), or an iron-rich slag-like geological specimen

Tumbled sandstone pebble

Sandstone, primarily quartz (SiO₂) with feldspar and iron-oxide cement

Pink Agate

Chalcedony (SiO2)