Man Made Glass

Fired Clay Brick (Anthropic Rock substitute)

Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)

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.

Goldstone and pink quartz bead strands

Goldstone is aventurescent copper-bearing glass; pink beads are likely rose quartz (SiO₂), though dyed or glass imitations are possible

Sea Glass

Amorphous Silica (Glass) SiO2

Milky quartz pebble

Quartz, silicon dioxide (SiO₂)

Blue glassy cabochon, likely blue quartz or synthetic glass

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

Likely milky quartz fragment

Quartz (SiO₂)

Blue Sea Glass

Amorphous Silica (Anthropogenic glass)

Tumbled orange-and-white feldspar-rich stone, likely sunstone or orange feldspar

Likely potassium feldspar (orthoclase or microcline), KAlSi₃O₈; exact identification is uncertain from the image

Nickel coin (U.S. currency)

Cupronickel (75% Copper, 25% Nickel alloy)

Red glass-like crystal, likely synthetic ruby or red glass

Uncertain from image; possible corundum (ruby), Al₂O₃, or synthetic glass

Cullet Glass (Strawberry Glass)

Amorphous Silicon Dioxide (SiO2) with metallic dopants

Beaded gemstone bracelet

Indeterminate; likely small polished mineral beads, possibly turquoise or dyed stone, with metal and glass components

Obsidian

Volcanic glass (SiO2)

Green Aventurine

Silicon Dioxide (SiO2+KAl2(AlSi3O10)(OH)2)

Chert (Flint)

Silicon dioxide (SiO2)

Green obsidian (likely moldavite)

Natural volcanic glass; if extraterrestrial-impact glass, moldavite (tektite)

Tumbled green glassy mineral, possibly aventurine or fluorite

Uncertain; likely quartz variety (aventurine quartz, SiO₂) or green fluorite (CaF₂)

Chert

Chert (Microcrystalline Quartz)

Likely chert (flint) fragment

Microcrystalline quartz, SiO₂

Colorless faceted gemstone, likely quartz

Quartz (SiO₂), tentative identification; the photo is insufficient to confirm the material

Flint (gray chert)

Microcrystalline quartz (SiO₂), a variety of chert

Pearl and Garnet Glass

Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass

Flint (chert) fragment

Microcrystalline quartz (SiO₂), commonly called flint when dark

Red cabochon gemstone ring

The stone may be carnelian (orange-red chalcedony, SiO₂); the image is insufficient to identify it reliably.

Weathered chert or chalcedony nodule

Microcrystalline quartz (SiO₂), possibly silicified limestone or agate-like chalcedony

Blue Slag Glass

Ferro-silicate glass (Slag)

Pumice

Pumice (Vesicular volcanic glass)

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Black tumbled stone, possibly obsidian

Obsidian (natural volcanic glass; composition varies, typically silica-rich)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (specifically Jasper or Flint)

Cryptocrystalline Quartz (SiO2)

Chert (Flint/Jasper variety)

Microcrystalline Quartz (SiO2)

Polished, carved gemstone (possibly dyed agate or glass-like material)

Unconfirmed from the image; no specific mineral can be identified reliably

Polished blue chalcedony (possibly agate)

Microcrystalline quartz, SiO₂; chalcedony, potentially banded agate

Faceted clear gemstone ring, likely quartz or glass imitation

Unidentified colorless faceted material; quartz (SiO₂) is possible, but the image cannot distinguish it from glass or another gem

Blue glass-like tumbled specimen

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

Diamond (or Diamond Simulant)

Carbon (C) or Cubic Zirconia (ZrO2)

Faceted Glass (Costume Jewelry)

Amorphous Silicon Dioxide with colorants (Glass)

Malaysian 50 Sen Coin

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

Pumice

Pumice (Vitreous volcanic rock)

Tumbled chert or jasper pebble

Microcrystalline quartz (SiO₂), likely chert/jasper