Not A Natural Rock (Man Made Composite)

Likely iron-rich slag or weathered ironstone fragment

Uncertain; possibly iron oxide–rich material (hematite/goethite) or industrial iron slag

Purple glassy pebble, possibly slag glass

Unidentified; likely man-made glass rather than a natural mineral

Cobalt Blue Glass / Cullet Glass

Silicon dioxide (Amorphous man-made glass)

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

Granite with Cupules / Bedrock Mortars

Granite (felsic intrusive plutonic rock)

Titanium Aura Quartz

Titanium bonded Silicon Dioxide (SiO2 + Ti)

Aura Quartz (Titanium Quartz)

Titanium-coated Silicon Dioxide (SiO2 + Ti)

Diamond (or Simulant)

Carbon (C)

Aura Quartz (Titanium-coated Quartz)

Silicon Dioxide (SiO2) with metallic vapor coating

Obsidian

Volcanic Glass

Obsidian

Volcanic glass

Asphalt aggregate (crushed stone in bitumen)

Artificial composite; predominantly crushed granite, basalt, limestone, and/or recycled aggregate bound by bitumen

Green glass sphere/marble

Soda-lime glass (primarily SiO2, Na2O, CaO)

Slag

Metallurgical Slag

Ring with an Orange Inlay

N/A (Man-made object)

Blue Obsidian (Cullet Glass)

Silicon Dioxide (Amorphous Glass)

Green glass-like cabochon, likely synthetic glass or resin

Unidentified green transparent material; possibly molded glass, synthetic spinel, or resin

Polished black pebble, likely basalt

Basalt, a fine-grained mafic volcanic rock composed mainly of plagioclase feldspar and pyroxene, commonly with olivine

Sea Glass

Amorphous silicon dioxide (Man-made glass weathered by wave action)

Costume Jewelry with Synthetic Gemstones

Synthetic Cubic Zirconia and Glass (SiO2 / ZrO2)

Opalite

Synthetic Glass (Hydrated Silica Simulant)

Sandstone Anvil / Nutting Stone

Quartzose Sandstone (Sedimentary Rock)

Polymer Clay (Mock Mineral)

Polyvinyl chloride (PVC) with plasticizers and pigment

Opalite

Synthetic Glass (SiO2 + impurities)

Clear quartz tumbled stone

Quartz (silicon dioxide, SiO₂)

Opalite

Synthetic Glass (Amorphized Silicon Dioxide)

Opalite

Synthetic Glass (Simulated Opal)

Aura Quartz

Titanium or Gold bonded Silicon Dioxide (SiO2)

Opalite

Man-made Opalized Glass (Synthetic Glass)

Opalite

Synthetic Opalized Glass (SiO2 + additives)

Polymictic conglomerate or breccia (possibly concrete-like aggregate)

Lithified polymictic gravel; clasts may include basalt, granite, quartzite, and other silicates

Dyed Imperial Jasper (Sea Sediment Jasper)

Silicon Dioxide (SiO2) - Impure Quartz/Chalcedony

Opalite glass sphere (likely synthetic imitation)

Man-made opalescent glass; not natural opal

Aura Quartz (specifically Titanium Aura Quartz)

Titanium-coated Silicon Dioxide (SiO2 + Ti Coating)

Opalite (Synthetic Moonstone/Opal)

Synthetic Silica Glass

Asphalt (Bituminous Concrete)

Bituminous Concrete / Pavement

Decorated turquoise-like bead or mineral pendant

Likely turquoise [CuAl₆(PO₄)₄(OH)₈·4H₂O], possibly dyed composite or blue-green jasper

Opalite

Synthetically produced glass (Silicon Dioxide with metallic inclusions)

Slag Glass

Vitreous Silicate Residue

Concrete with Exposed Aggregate

Anthropogenic conglomerate (Concrete)

Concrete with Aggregate

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

Titanium Aura Quartz

Silicon Dioxide (SiO2) coated with Titanium and Niobium