Not A Natural Rock (Man Made Composite)

Polished tiger iron

Tiger iron; interlayered hematite, jasper, and crocidolite-quartz (often riebeckite)

Milky quartz (likely)

Quartz, silicon dioxide (SiO₂)

Tumbled black stone, likely black obsidian

Obsidian (volcanic glass; chiefly silica-rich rhyolitic composition)

Carved Mottled Greenish-Yellow Crystal/Glass Object

Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.

Blue Goldstone

Aventurine Glass

Basalt with Red Sandstone

Mafic extrusive igneous rock with quartzose sedimentary matrix

Likely beach-worn glass and a pebble

The brown piece appears to be weathered glass (amorphous SiO₂-rich material); the pale piece is likely a small quartz-rich stone, possibly milky quartz.

Raw turquoise-bearing rock

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O, likely in a limonite/matrix host

Blue Slag Glass

Anthropogenic Amorphous Silicon Dioxide

Sandstone

Arenite (composed primarily of SiO2)

Ruby in Zoisite

Anyolite (composite of Corundum and Zoisite)

Hematite Beads

Hematite (Fe2O3)

Blue Goldstone

Synthetic glass with cobalt and copper inclusions

Slag (Industrial By-product)

Glassy silicate or metallic smelting residue

Sea Glass

Man-made silicate glass (Amorphous silicon dioxide)

Ruby ring

Corundum (Al₂O₃), red variety colored mainly by chromium

Small clear crystal, possibly quartz or glass-like gemstone

Uncertain; likely quartz (SiO₂), but the image is insufficient to exclude man-made glass or cubic zirconia

Polished chrysocolla-matrix stone (probable)

Chrysocolla, hydrated copper aluminosilicate; likely mixed with quartz, turquoise, or copper minerals

Man-made Blank Ammunition (Brass)

CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)

Sandstone

Arenite (with iron oxide cement)

Brecciated Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Tumbled sea glass or pale-green quartz pebble

Indeterminate from image; possibly quartz (SiO₂), but the smooth translucent piece may be man-made glass

Likely tumbled red mineral or glass imitation

Indeterminate; possibilities include red jasper (microcrystalline quartz, SiO₂) or dyed chalcedony

Blue glass-like tumbled specimen

Most likely cobalt-blue slag glass or manufactured glass; not confidently identifiable as a natural mineral from the image

Rough Sapphire (Corundum)

Corundum (Al2O3)

Beaded mineral/crystal jewelry (likely turquoise and coral accents)

Variable; blue beads may be turquoise (CuAl6(PO4)4(OH)8·4H2O), with possible dyed howlite, glass, or composite materials

Concretion with Geode Cavity

Ferruginous Sandstone Concretion with Quartz Center

Sea Glass

Man-made vitreous material (silica-based glass)

Sea Glass

Man-made vitreous material (silica glass)

Goldstone

Man-made glass infused with metallic copper

Sea Glass

Man-made silicate glass weathering product

Diamond (in a gold ring)

Diamond (pure carbon, C)

Dyed and polished agate cabochon

Microcrystalline quartz (chalcedony), SiO₂; likely colored or composite agate

Bismuth Crystal

Bismuth (Bi)

Goldstone

Man-made glass infused with copper crystals

Blue Sandstone

Man-made glass with cobalt and copper inclusions

Goldstone

Man-made glass containing cuprous oxide

Chalk

Calcium carbonate (CaCO3)

Chalk

Calcium Carbonate (CaCO3)

Yellow cabochon gemstone, likely citrine or yellow glass imitation

Quartz (SiO₂), if natural citrine; visual evidence is insufficient to exclude man-made glass or resin

Tumbled milky quartz

Quartz — silicon dioxide (SiO₂), cryptocrystalline or microcrystalline variety possible

Green Aventurine

Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2AlSi3O10(OH)2)