Mineraloid (Man Made Glass)

Pet Rock (Man-made Quartzite or Granite Cobble)

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

Sandstone Anvil / Nutting Stone

Quartzose Sandstone (Sedimentary Rock)

Pink Tumbled Quartz (Dyed)

Silicon Dioxide (SiO2)

Dyed Crackle Quartz (Green)

Quenching-treated Quartz (Silicon Dioxide, SiO2)

Quartzite (Engineered Stone)

Silicon Dioxide (SiO2) based synthetic composite

Chert Concretion (with typical hematite/limonite staining)

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

Sandstone Concretion

Clastic Sedimentary Rock (primarily SiO2 with mineral cement)

Pyrite Concretion (Grapestone)

Iron Sulfide (FeS2) Concretion

Obsidian

Volcanic Glass (Amorphous SiO2)

Note: This is a Man-Made Object (Costume/Prop Patch)

Synthetic fiber and pigments (Cellulose/Plastic-based composite)

Man-made Synthetic Material (Plastic/Composite)

Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)

Black Obsidian

Volcanic Glass (Amorphous SiO2)

Goldstone (blue/black aventurine glass)

Man-made aventurine glass; silica glass containing metallic copper or other glittering inclusions

Polished blue-green glassy slag or coated mineral fragment

Most likely man-made colored glass/slag; exact composition cannot be determined visually

Obsidian

Volcanic Glass

Obsidian

Volcanic Glass

Aura Quartz (Titanium/Gold coated)

Silicon Dioxide (SiO2) with metallic vapor deposition

Blue slag glass or dyed glass-like industrial material

Amorphous silicate glass; likely copper-bearing blue slag, but possibly colored man-made glass

Aura Quartz

Titanium/Titanium-Gold treated Silicon Dioxide (SiO2)

Obsidian

Volcanic Glass (Amorphous silicon dioxide with impurities)

Yellow cabochon gemstone, likely citrine or yellow glass imitation

Quartz (SiO₂), if natural citrine; visual evidence is insufficient to exclude man-made glass or resin

Black Obsidian

Volcanic glass

Obsidian

Volcanic Glass

Small clear crystal, possibly quartz or glass-like gemstone

Uncertain; likely quartz (SiO₂), but the image is insufficient to exclude man-made glass or cubic zirconia

Metal Alloy (Likely Pewter or Sterling Silver)

Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).

Tumbled sea glass or pale-green quartz pebble

Indeterminate from image; possibly quartz (SiO₂), but the smooth translucent piece may be man-made glass

Baked-clay ceramic fragment (likely brick or pottery)

Fired clay, primarily aluminosilicate minerals; not a natural rock

Conglomerate

Conglomerate Rock (Paraconglomerate)

Sandstone Concretion

Clastic sedimentary rock (primarily Quartz SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Titanium Amethyst Geode

Silicon Dioxide (SiO2) with Titanium/Metal Vapor Deposition Layer

Vesicular basalt (weathered scoria)

Scoriaceous basalt; chiefly plagioclase, clinopyroxene, olivine, and iron-titanium oxides

Black Obsidian

Volcanic Glass (predominantly SiO2)

Obsidian

Volcanic glass

Obsidian

Volcanic glass

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Sea Glass (Frosted Glass)

Amorphous Silica (SiO2) with various additives

Blue tumbled glass-like specimen; likely blue slag glass

Likely man-made glass (silicate glass), not a natural mineral; exact material cannot be confirmed from the image

Snowflake Obsidian

Spherulitic Volcanic Glass (primarily SiO2)

Blue Crackle Quartz (Dyed Quarzite)

Silicon Dioxide (SiO2) with artificial dye

Dyed Blue Agate (Dragon Vein Agate)

Silicon Dioxide (SiO2) with artificial cobalt/organic dyes

Diamond

Native Carbon (C)