Anthropogenic (Man Made)

Opalite

Man-made Synthetic Glass (Silicon Dioxide with metal additives)

Opalite

Synthetic Opalite Glass

Silicon Carbide (Carborundum)

Silicon Carbide (SiC)

Red Sandstone or Brick Fragment

Arenite (if sandstone)

Titanium Coated Kyanite (Aura Kyanite)

Aluminosilicate (Al2SiO5) with a Titanium-Niobium vacuum-deposited coating

Cherry Quartz

SiO2 (Silicon Dioxide with iron-rich inclusions/dye)

Likely clear quartz pebble or glassy quartz fragment

Quartz (silicon dioxide, SiO₂)

Aventurine Quartz

Silicon Dioxide (SiO2) with Fuchsite inclusions

Moldavite

Tektite (Impact Glass), ~80% SiO2 + Al2O3

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite or Goethite inclusions

Cubic Zirconia (Man-made)

Cubic Zirconia (ZrO2) with Enamel and Metal Alloy

Tumbled opalite (likely man-made glass)

Opalite glass; a synthetic opalescent glass, not a natural mineral species

Bismuth

Bismuth (Bi)

Decorative mosaic cross containing mixed rock and glass fragments

Polychrome aggregate; likely quartz, feldspar, marble, granite, and assorted colored glass

Blue cabochon gemstone, likely synthetic glass or dyed stone

Indeterminate from image; possible glass, synthetic spinel, sodalite, or lapis lazuli

Sandstone (with man-made markings)

Arenite (composed primarily of Quartz, SiO2)

Cubic Zirconia (Diamond Simulant)

Zirconium Dioxide (ZrO2)

Opalite

Synthetic Opalised Glass

Opalite

Synthetic Silicon Dioxide (SiO2)

Rainbow Hematite (Titanium Coated)

Iron(III) oxide (Fe2O3) with Titanium/Metal Oxide coating

Blue opalite glass (likely man-made)

Opalite glass; a silica-based amorphous glass, not natural opal

Tumbled opalite (likely man-made glass)

Opalite, a trade name for opalescent glass; not natural opal

Opalite (likely imitation opal glass)

Man-made opalescent glass; not a natural mineral (often sold as opalite)

Blue glassy-looking specimen, possibly dyed or coated mineral

Not identifiable from the photograph; possibilities include dyed quartz or glassy slag, but composition cannot be established visually.

Milky quartz (rough quartz fragment)

Quartz, silicon dioxide (SiO₂)

Chert Concretion

Chert (Microcrystalline Quartz, SiO2)

Crescent Pebble

Weathered Quartzite or Sandstone Fragment

Polished brown jasper (likely brecciated or orbicular jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions

Likely tumbled or cut quartz/chalcedony fragment

Silicon dioxide (SiO₂), probably microcrystalline quartz or quartz

Boxwork or Septarian Concretion

Septarian nodule / Boxwork weathering

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂), likely milky quartz

Clear quartz sphere

Quartz (silicon dioxide, SiO₂)

Sandstone (with concrete/human-made layer)

Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)

Mystic Topaz

Aluminum Silicate Fluoride Hydroxide (Al2SiO4(F,OH)2) with metallic film coating

Opalite

Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)

Obsidian (Blue)

Volcanic Glass (SiO2)

Blue Cracked Quartz (Dyed Fire Crackle Quartz)

Silicon Dioxide (SiO2) with synthetic dye

Slag

Metallurgical Slag

Pink Quartz / Sea Glass

Silicon Dioxide (SiO2)

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂)

White sea glass (naturally frosted glass fragment)

Man-made silicate glass, typically soda-lime glass; not a mineral or rock