Mineral (Man Made Glass)

Fossilized oyster shell

Bivalvia; likely an oyster (Ostreidae), partly mineralized with calcite

Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')

Calcite (Calcium Carbonate, CaCO3)

Coal (Anthracite / Bituminous)

Organic Sedimentary Rock (Carbon-based)

Red Jasper

Silicon Dioxide (SiO2) with Hematite inclusions

Obsidian

Obsidian (volcanic glass)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Coquina

Biogenic Limestone (Calcite/Aragonite base, CaCO3)

Pyrite

Iron Sulfide (FeS2)

Flint/Chert Nodule in Limestone

Sedimentary rock containing microcrystalline quartz (SiO2) within a calcium carbonate (CaCO3) matrix

Diorite

Intermediate plutonic igneous rock

Slate

Foliated Metamorphic Slate

Diamond in Kimberlite

Diamond (C in Kimberlite Matrix)

Amber (Copal)

Organic gemstone, fossilized tree resin (often immature amber or copal)

Turquoise bead bracelet

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Diamond

Diamond (pure Carbon, C)

Diorite

Diorite

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Megalodon Shark Tooth

Otodus megalodon

Diabase (Dolerite)

Diabase / Dolerite

Land Snail Shell

Gastropoda (Calcium Carbonate, CaCO3)

Carved quartz skull, likely smoky quartz or gray chalcedony

Silicon dioxide (SiO₂), quartz or microcrystalline quartz

Bituminous Coal (with Anthracite or Vitrinite inclusion)

Organic-rich Sedimentary Rock (Carboniferous classification)

Chert (Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Fossilized Shark Tooth (Fragment)

Elasmobranchii gen. et sp. indet. (Calcium Phosphate / Apatite fossil)

Pyrite

Iron Sulfide (FeS2)

Angel Aura Quartz (Treated Clear Quartz)

Silicon Dioxide (SiO2) coated with Vaporized Silver and Platinum

Fossilized Coral (Coquina/Limestone)

Cnidaria Anthozoa (Fossilized)

Chert (variations include Flint)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (White Chert/Flint)

Microcrystalline Quartz (SiO2)

Banded Sandstone

Arenite with Liesegang banding

Diamond

C (Native Carbon)

Diamond (Cut Gemstone)

Natural Carbon (C)

Granite

Phaneritic Plutonic Felsic Rock

Chert (specifically Yellow/Brown Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Native Silver

Silver (Ag)

Pearl-embellished decorative cross

Pearl (biogenic calcium carbonate, predominantly aragonite) with rhinestone-mounted glass or synthetic gemstones

Titanium Aura Quartz

Titanium-coated Silicon Dioxide (SiO2)

Lava Rock (Dyed)

Basalt / Volcanic scoria

Granite, possibly granodiorite

Coarse-grained felsic plutonic rock; chiefly quartz (SiO₂), potassium feldspar and plagioclase feldspar, with biotite and/or hornblende

Brecciated jasper (likely red-and-cream jasper)

Jasper, an opaque microcrystalline variety of quartz; primarily cryptocrystalline SiO₂ with iron-oxide staining and possible chalcedony/quartz veining

Pearl (with Peridot)

Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4