Tektite (Natural Glass)

Quartzite

Quartzite (SiO2)

Sandstone

Arenite (with iron oxide cement)

Sandstone

Arenite

Sandstone

Arenite

Sandstone (Quartz-rich)

Arenite (composed mainly of SiO2)

Sandstone (Quartzose)

Arenite (primarily SiO2)

Sandstone (Quartzose)

Arenite (composed primarily of SiO2)

Tumbled obsidian

Volcanic glass; chiefly silica-rich rhyolitic glass (approximately 70–80% SiO₂)

Crackle Glass (Simulated Gemstone)

Amorphous Solid (SiO2)

Gemstone rings (stones not reliably identifiable)

The pale stone may be quartz or another translucent gem; the red stone may be ruby, garnet, or synthetic corundum. Image detail is insufficient for identification.

Orange glassy slag (industrial by-product)

Iron-rich silicate glass; composition varies, commonly Fe–Ca–Al silicate

Green aventurine (likely)

Quartz variety; silicon dioxide (SiO₂) with fuchsite mica inclusions

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Limonite/Hematite)

Milky Quartz Pebble

Silicon Dioxide (SiO2)

Citrine Quartz Sphere

Silicon Dioxide (SiO2)

Colorless faceted gemstone, likely quartz

Quartz (SiO₂), probably rock crystal; exact identification is uncertain from the strongly backlit image

Quartzite with Hag Stone Feature

Quartzite (SiO2)

Orange Quartz (Citrine or Iron-stained Quartz)

Silicon Dioxide (SiO2)

Tumbled blue gemstone, likely blue quartz or dyed chalcedony

Quartz (SiO₂), possibly chalcedony; exact identification requires testing

Tumbled blue chalcedony (likely blue quartz/chalcedony)

Cryptocrystalline silica, SiO₂; likely chalcedony, possibly dyed or surface-coated

Snowflake Obsidian

Obsidian with Cristobalite inclusions (70-75% SiO2)

Quartz crystal cluster

Quartz (SiO₂), likely iron-stained; exact variety uncertain

Quartz Pebble

Silicon Dioxide (SiO2)

Chert / Flint

Microcrystalline Quartz (SiO2)

Quartz (Smoky Quartz)

Silicon Dioxide (SiO2)

Blue-stone ring, likely set with blue glass or a dark-blue gemstone

The stone cannot be identified reliably from the image; possible sapphire (corundum, Al₂O₃), lapis lazuli, or glass

Cullet Glass (Slag Glass)

Amorphous Silicon Dioxide (SiO2) with metallic oxide impurities

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Citrine Quartz

Silicon Dioxide (SiO2) with ferric iron impurities

Yellow Quartz (Citrine/Yellow Jasper)

Silicon Dioxide (SiO2)

Citrine Quartz

Silicon Dioxide (SiO2)

Tumbled yellow quartz (likely citrine or iron-stained quartz)

Quartz, silicon dioxide (SiO₂), colored yellow by iron impurities; possibly heat-treated amethyst

Obsidian (likely snowflake or banded variety)

Volcanic glass, primarily SiO₂

Tumbled green glassy mineral, possibly aventurine or fluorite

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

Faceted colorless gemstone, likely quartz or glass imitation

Most plausibly rock crystal (quartz, SiO₂); identity is uncertain because the photograph shows only intense facet reflections

Rose Quartz and Cherry Quartz (Dyed Glass/Quartz)

Silicon Dioxide (SiO2) with inclusions/dye

Pumice

Pumice (Felsic volcanic glass)

Polished blue glassy mineral specimen, likely sodalite or blue aventurine

Most consistent with sodalite (Na₈Al₆Si₆O₂₄Cl₂), though dyed quartzite or blue glass cannot be excluded from the photograph

Blue gemstone bead bracelet, likely lapis lazuli or dyed stone

Uncertain from image; possible lazurite-bearing lapis lazuli (Na₃Ca(Si₃Al₃)O₁₂S) or dyed quartz/glass imitation

Blue Goldstone

Man-made glass with suspended copper, cobalt, or manganese particles

Green quartz bead bracelet

Quartz, silicon dioxide (SiO₂), likely green aventurine or prasiolite; exact identification requires testing

Quartz pebble in concrete

Quartz (SiO₂), embedded in Portland-cement concrete