Mineral Based Human Made Alloy

Polished banded calcite (often sold as “onyx marble” or Mexican onyx)

Banded calcite; predominantly CaCO₃, usually microcrystalline to fibrous calcite

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (Flint)

Cryptocrystalline Quartz (SiO2)

South Korean 100 Won Coin (Cupronickel)

Cupronickel Alloy (75% Cu, 25% Ni)

Chalcedony / milky quartz flake

Microcrystalline quartz (SiO₂), likely chalcedony; possibly a worked quartzite or chert fragment

Bismuth

Bismuth (Bi)

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Banded Sandstone

Arenite with Liesegang banding

Chert (with Limestone matrix)

Silicon dioxide (SiO2)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Serpentine-rich metamorphic rock (probable serpentinite)

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile), commonly with magnetite and chromite

River Pebble

Weathered Rock Fragment

Asphalt Concrete

Bituminous Concrete / Asphaltic Composite

Ferrochrome Slag

Calcium-Aluminium-Magnesium Silicate Slag

Opalite-style pendant (likely synthetic glass, not natural opal)

Opalescent glass; commonly sold as “opalite” (not a recognized mineral species)

Iron Meteorite

Siderite (Iron-Nickel Alloy)

Granite

Granite (a plutonic rock)

Blue-green gemstone ring, likely treated turquoise or synthetic/treated beryl

Indeterminate from image; possibilities include turquoise (CuAl6(PO4)4(OH)8·4H2O), apatite, or treated beryl

Mixed beach-stone and tumbled-glass collection

Predominantly uncertain rocks (likely basalt, granite, and quartz-bearing stones) with anthropogenic glass; one possible banded agate or jasper

Likely smoky quartz pendant

Smoky quartz, silicon dioxide (SiO₂), quartz variety colored by irradiation-related defects

Chert (Flint Arrowhead)

Silicon Dioxide (SiO2)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Chert

Silicon dioxide (SiO2)

Costume Jewelry with Synthetic Gemstones

Synthetic Cubic Zirconia and Glass (SiO2 / ZrO2)

Greenstone / serpentinite carving

Serpentinite, chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile); exact identification requires testing

Blue glassy cabochon, likely blue quartz or synthetic glass

Possibly dyed blue chalcedony/quartz (SiO₂); visual identification is inconclusive

Malaysian 50 Sen Coin

Coinage (specific alloy unknown without metallurgical analysis, but typically brass or bronze for this denomination and era)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Arsenic (Native)

Arsenic (As)

Green cabochon gemstone, likely nephrite jade

Nephrite jade—interlocking amphibole fibers, chiefly tremolite-actinolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂

Colorless faceted gemstone, likely glass or quartz

Uncertain; possibly quartz (SiO₂), but the strong uniform brilliance and apparent molded/faceted form may indicate leaded glass or cubic zirconia

Tumbled cream-colored pebble

Likely quartz-rich sandstone or limestone; exact identification requires testing

Fossilized Coral (Petoskey-style)

Hexagonaria percarinata (Fossilized Rugose Coral)

Granite

Phaneritic Plutonic Felsic Rock

Dyed Blue Agate Slice

Silicon Dioxide (SiO2)

Blue-dyed Quartz Druzy

Silicon Dioxide (SiO2) with artificial pigment

Granite

Granite (composed primarily of Quartz, Feldspar, and Mica)

Tumbled opalite (likely synthetic glass)

Opalite; typically man-made opalescent soda-lime glass, not a recognized mineral species

Blue Celestite

Celestine (Strontium Sulfate, SrSO4)

Polished black stone egg, probably black obsidian

Obsidian, a natural volcanic glass; composition primarily silica-rich glass (approximately SiO₂), with variable iron and other trace elements

Chert (Arrowhead Shard)

Microcrystalline silica (SiO2)

White flint or chert flake

Microcrystalline quartz (SiO₂), likely chert/flint