Sedimentary (Man Made Composite)

Petoskey Stone

Hexagonaria percarinata

Turquoise

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

Diamond

Carbon (C)

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

Marble

Recrystallized Calcite (CaCO3)

Rough Diamond

Diamond (Pure Carbon: C)

Banded agate pendant (likely carnelian or brown-and-white chalcedony agate)

Agate, a banded variety of chalcedony; microcrystalline quartz, SiO₂, with iron-oxide coloration

White Marble

Metamorphic Limestone (CaCO3)

Diamond

Carbon (C)

Pearl-embellished decorative cross

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

Goldstone

Avventurina (Cu + SiO2 glass)

Amethyst

SiO2 (Silicon Dioxide)

White Marble

Recrystallized Calcite (CaCO3)

Pearl (Biogenic Mineraloid)

Calcium carbonate (Aragonite) and Conchiolin, CaCO3

Chalcanthite (Likely Synthetic/Lab-Grown)

Hydrated copper(II) sulfate (CuSO4·5H2O)

Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')

Silicon Dioxide (SiO2) with artificial pigment

Granite

Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).

Granite

Granite (felsic intrusive igneous rock)

Sea Glass (Teal/Turquoise)

Amorphous Silica (SiO2) with trace metal oxides

Sea Glass (Turquoise/Aqua)

Amorphous Silica (SiO2) with transition metal dopants

Diamond

Carbon (C)

Weathered pegmatite or feldspar-rich granite fragment

Granitic pegmatite, composed mainly of potassium feldspar and quartz, with minor mica; exact identification is uncertain from the photograph

Amber (Copal)

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

Fossilized Stingray Mouth Plate

Myliobatidae gen. et sp. indet. (e.g., Myliobatis, Aetobatus)

Sea Glass (Frosted Glass)

Amorphous Silica (SiO2) with various metal oxide impurities

Metal Alloy (Jewelry)

Not a naturally occurring rock or mineral; likely a metal alloy for jewelry. Possible compositions include sterling silver (92.5% silver, 7.5% copper), or other silver/gold alloys.

United States Quarter Dollar

Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)

Green Glass Cullet / Recycled Glass

Amorphous Silicon Dioxide (SiO2) with various metal oxides

Obsidian

Obsidian (volcanic glass, amorphous silica rich rock)

Quartz

Silicon Dioxide (SiO₂)

BROWN GRANITE (likely 'Tan Brown' or similar)

Granite (specifically a variety rich in orthoclase feldspar, often with biotite and possibly hornblende)

Mixed Gemstone Beaded Jewelry

Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)

Granite, possibly granodiorite

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

Fordite

Anthropogenic paint-rock

Goldstone

Not a natural mineral or rock. It is an ornamental glass.

Basalt

Basalt

Muscovite Mica

Muscovite (Potassium Aluminum Silicate Hydroxide Fluoride), KAl2(AlSi3O10)(OH,F)2

Tumbled sodalite with white calcite veining

Sodalite, Na8(Al6Si6O24)Cl2, commonly intergrown with calcite, CaCO3

Granite Cobble/Pebble

Granite

Granite (weathered pebble)

Granite (plutonic igneous rock)

Jade (likely Nephrite Jade based on appearance)

Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)

Titanium Aura Quartz

Titanium-coated Silicon Dioxide (SiO2)