Man Made Silicate (Anthropogenic Glass)

Green obsidian (likely moldavite)

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

Mixed polished gemstone and mineral collection

Primarily quartz varieties (SiO₂), plus probable aventurine, rose quartz, amethyst, agate, jasper, serpentine, feldspar, and possibly dyed or man-made glass pieces

Tumbled green glassy mineral, possibly aventurine or fluorite

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

Unidentified Dark Mineral or Rock

Indeterminate (Likely Silicon Dioxide or Carbon-based)

Chert

Chert (Microcrystalline Quartz)

Quartzite pebble

Metamorphic Quartzite (SiO2)

Sea Glass

Amorphous Silica (SiO2) with various additives

Blue Slag Glass

Amorphous Silica (Industrial byproduct)

Red Slag Glass (Cullet)

Amorphous Silicon Dioxide (SiO2) with metallic dopants

Pumice

Pumice (Vesicular volcanic glass)

Red cabochon gemstone ring

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

Quartz (Small Pebble)

Silicon Dioxide (SiO2)

Mineral and Rock Collection (Assorted)

Mixed collection including Quartz (SiO2), Jasper (SiO2 with impurities), Rose Quartz, and Aventurine

Quartz-rich river pebble (likely milky quartz or quartzite)

Quartz, SiO₂; possibly quartzite, a metamorphic rock dominated by quartz

Chert (Flint/Jasper variety)

Microcrystalline Quartz (SiO2)

Pearl and Garnet Glass

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

Tektite (Indochinite)

Tektite (Amorphous Silica Glass)

Tumbled smoky quartz pebble (probable)

Quartz, SiO₂; smoky variety colored by irradiation-related defects

Weathered chert or chalcedony nodule

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

Chipped Glass/Plastic Fragment

Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic

Red Jasper

Silicate (SiO2 with Hematite impurities)

Black obsidian (likely)

Volcanic glass; predominantly silica-rich, non-crystalline silicate glass

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (specifically Jasper or Flint)

Cryptocrystalline Quartz (SiO2)

Green Aventurine

Aventurine Quartz (SiO2 with inclusions)

Potassium Feldspar (Orthoclase / Microcline)

KAlSi3O8 (Potassium Aluminum Silicate)

Unidentified brown mineral/rock fragment

Indeterminate from image; possibly iron-stained quartz, feldspar, or weathered limonite

Pumice

Pumice (Vitreous volcanic rock)

Malaysian 50 Sen Coin

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

Quartz (Iron-stained)

Silicon Dioxide (SiO2) with hematite/limonite inclusions

Pink Granite

Phaneritic Felsic Igneous Rock (Granite)

Polished blue chalcedony (possibly agate)

Microcrystalline quartz, SiO₂; chalcedony, potentially banded agate

Potassium Feldspar (Orthoclase Pebble)

KAlSi3O8 (Potassium aluminum silicate)

Orthoclase Feldspar

KAlSi3O8 (Potassium aluminum silicate)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)

Blue glass-like tumbled specimen

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

Chert

Microcrystalline Quartz (SiO2)

Quartzite

Quartzite (primarily SiO2)

Quartz (Iron-Stained or Milky Quartz)

Silicon Dioxide (SiO2)

Green Slag Glass

Amorphous Silica / Glassy Blast Furnace Slag

Sandstone (Water-worn Cobble)

Arenite (SiO2 with CaCO3 or Fe2O3 cement)