Not A Rock (Man Made Origin)

Opalite

Synthetic Glass (Simulated Moonstone/Opal)

Diamond (or Cubic Zirconia)

Carbon (C) or Zirconium Dioxide (ZrO2)

Goldstone

Aventurine glass (Synthetic glass with copper inclusions)

Vesicular Basalt (Iron Scoria)

Aphanitic Mafic Igneous Rock with Vesicular Texture

Quartz (likely milky quartz or quartz glass-like fragment)

Quartz, silicon dioxide (SiO₂)

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

Cherry Quartz with Rose Quartz

Crystalline Quartz (SiO2) with glass-based synthetic components

Blue Goldstone

Aventurine Glass

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Faceted clear gemstone, likely quartz or glass imitation

Most likely quartz (SiO₂); exact identification requires refractive-index and hardness tests

Black tumbled stone, possibly obsidian

Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image

Rounded graywacke or sandstone cobble

Lithified clastic sandstone; likely quartz–feldspar–lithic grain aggregate in a silica or calcite matrix

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Opalite

Synthetic Opalized Glass

Slag Glass / Industrial Slag

Anthropogenic Glass

Fluorite (Polished Point/Tower)

Calcium Fluoride (CaF2)

Goldstone (Red)

Aventurine Glass (Cupriferous glass)

Aura Quartz

Titanium-coated Silicon Dioxide (SiO2)

Concrete with Aggregate

Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)

Ferrochrome Slag

Anthropogenic slag (Fe-Cr alloy waste)

Unidentified polished dark gemstone cabochon

Possibly hematite, obsidian, jet, or dark agate; image insufficient for a definitive identification

Painted beach pebble

Unidentified natural pebble; underlying lithology cannot be determined from the image

Possibly garnet-bearing rock fragment

Unidentified reddish-brown mineral or rock; the image is insufficient for a reliable species identification.

Cubic Zirconia (Simulated Diamond)

Cubic Zirconia (ZrO2)

Opalite

Synthetic Opalite Glass (Silicon Dioxide)

Blue Glass or Slag Glass

Amorphous Silica (Anthropogenic Glass)

Blue-dyed tumbled quartz or glass imitation

Quartz (SiO₂), appearance possibly enhanced with blue dye; identity uncertain from image

Sea Glass

Amorphous silicon dioxide (SiO2) - Man-made glass tumbled by nature

Blue Goldstone

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

Black glassy fragment, likely obsidian or industrial glass

Volcanic glass (obsidian), chiefly amorphous SiO₂; identification uncertain from image

Diamond (in a jewelry setting)

Cubic Carbon (C)

Chert (and Flint)

Silicon Dioxide (SiO2)

Green glass cabochon or tumbled stone

Indeterminate; likely man-made glass, possibly aventurine glass rather than a natural mineral

Milky quartz (likely quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

Blue opal heart cabochon

Common opal, hydrated amorphous silica (SiO₂·nH₂O), likely blue-dyed or synthetic opalite

Sea Glass (White/Clear)

Amorphous Silica (Alkali-Lime-Silica Glass), SiO2 + Na2O + CaO

Quartz crystal (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Polished gemstone tower assortment

Primarily quartz varieties and simulants; apparent amethyst (SiO₂), rose quartz (SiO₂), clear quartz (SiO₂), fluorite (CaF₂), sodalite, malachite, and possibly dyed or composite stones

Polished black stone, likely black obsidian

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

Pink Tumbled Quartz (Dyed)

Silicon Dioxide (SiO2)

Dyed Crackle Quartz (Green)

Quenching-treated Quartz (Silicon Dioxide, SiO2)