Anthropogenic Material (Man Made Rock)

Tumbled opalite (likely man-made glass)

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

Quartzite (Engineered Stone)

Silicon Dioxide (SiO2) based synthetic composite

Obsidian (likely black volcanic glass)

Obsidian; primarily amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition

Rock crystal quartz fragments

Quartz (silicon dioxide, SiO₂)

Green Obsidian Sphere (man-made glass)

Vitreous Silica with Chromium/Iron additives

Tumbled milky quartz (likely)

Quartz, silicon dioxide (SiO₂)

Black glassy fragment, likely obsidian or industrial glass

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

Green glass cabochon or tumbled stone

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

Polished dendritic agate or jasper

Microcrystalline quartz (SiO₂), likely chalcedony with iron/manganese dendrites

Faceted clear gemstone, likely quartz or glass imitation

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

Chert Arrowhead

Microcrystalline Quartz (SiO2)

Rounded graywacke or sandstone cobble

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

Man-made Jewelry (Metal and Glass/Plastic)

Synthetic Alloy and Amorphous Solid (SiO2/Polymer)

Mystic Topaz (Treated Quartz or Topaz)

Aluminum silicate fluoride hydroxide [Al2SiO4(F,OH)2] with thin-film metallic coating

Sandstone Concretion

Limonitic Sandstone Concretion

Vesicular basalt (probable iron-rich volcanic rock)

Basalt; chiefly plagioclase, clinopyroxene, olivine, and Fe-Ti oxides

Diamond

Carbon (C)

Opalite

Synthetic Opalite (Man-made glass)

Cullet Glass (Slag)

Amorphous Silicon Dioxide (Man-made)

Green Sea Glass

Man-made silicate glass (weathered)

Polished black pebble, possibly obsidian

Volcanic glass (obsidian), likely; identification is tentative from the image

Terrazzo (with Marble and Granite fragments)

Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates

Opalite (likely man-made glass)

Opalite; amorphous silica glass, not a natural mineral

Terracotta (Man-made ceramic brick fragment)

Baked clay / High-iron ceramic (Silicate-based ceramic)

Green obsidian (likely molded or heat-treated glass-like specimen)

Volcanic glass; predominantly rhyolitic composition (silica-rich amorphous SiO₂)

Carborundum (Silicon Carbide)

Silicon Carbide (SiC)

Man-made earbud charging case (Not a rock or mineral)

Acrylonitrile Butadiene Styrene (ABS) Plastic with electronic components

Polished white chalcedony or quartz pendant

Microcrystalline quartz (chalcedony), SiO₂; exact identification is uncertain from the image

Baked-clay ceramic fragment (likely brick or pottery)

Fired clay, primarily aluminosilicate minerals; not a natural rock

Man-made Ceramic / Clay Figurine

Aluminosilicate Ceramic (Processed Clay)

Sandstone Concretion

Clastic sedimentary rock (primarily Quartz SiO2)

Sandstone Concretion

Clastic Sedimentary Rock (primarily SiO2 with mineral cement)

Blue opal heart cabochon

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

Titanium-coated Metal Cube (Man-made Fidget Toy)

Titanium-anodized or electroplated alloy (e.g., Ti-coated Zinc or Aluminum)

Green sea glass (likely bottle glass)

Man-made soda-lime silicate glass; not a natural mineral

Polished black stone, likely black obsidian

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

Milky quartz (rough fragment)

Quartz, silicon dioxide (SiO₂)

Tumbled milky chalcedony (likely common opalite-like quartz)

Chalcedony, microcrystalline SiO₂; possibly pale common opal, hydrated SiO₂·nH₂O

Blue goldstone beads

Man-made aventurine glass (silica glass with metallic copper inclusions), not natural lapis lazuli

Opalite

Synthetic Glass (Silica-based)

Titanium Aura Quartz

Titanium bonded Silicon Dioxide (SiO2 + Ti)

Chert Concretion (with typical hematite/limonite staining)

Sedimentary Concretion (SiO2 with FeO(OH)⋅nH2O)