Anthropogenic (Man Made Material Processed By Nature)

Polished dendritic agate or jasper

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

Green sea glass or tumbled green quartz (uncertain)

Likely quartz (SiO₂) if natural; alternatively man-made soda-lime glass

Red Slag Glass (Cullet)

Amorphous Silicon Dioxide (SiO2) with metallic dopants

Lava Rock (Dyed)

Basalt / Volcanic scoria

Clear quartz tumbled stone

Quartz (silicon dioxide, SiO₂)

Concrete aggregate surface

Human-made cementitious composite; primarily calcium-silicate-hydrate cement with mixed silicate aggregate

Cubic Zirconia (CZ)

Cubic Zirconium Dioxide (ZrO2)

Agate (specifically, multi-colored or pastel-dyed agate)

Silicon dioxide (SiO2) - specifically, a cryptocrystalline variety of quartz known as Chalcedony, with banding classified as Agate. (If it were Fluorite, the chemical formula would be Calcium Fluoride - CaF2).

Fluorite (Polished Point/Tower)

Calcium Fluoride (CaF2)

Opalite

Synthetic Opalised Glass

Chert Arrowhead

Microcrystalline Quartz (SiO2)

Green Aventurine

Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)

Tumbled brown banded jasper

Microcrystalline quartz (SiO₂), commonly chalcedony with iron-oxide inclusions

Quartz crystal (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

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

Blue glassy cabochon, likely blue quartz or synthetic glass

Possibly dyed blue chalcedony/quartz (SiO₂); visual identification is inconclusive

Colorless faceted gemstone, likely glass or cubic zirconia

Uncertain; possible cubic zirconia (ZrO₂) or quartz (SiO₂), but the image may show a man-made simulant

Red glass-like crystal, likely synthetic ruby or red glass

Uncertain from image; possible corundum (ruby), Al₂O₃, or synthetic glass

Milky quartz (likely quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

Polished/tumbled brown-and-white mineral fragment

Indeterminate; possibly quartz-rich jasper, brecciated jasper, or an iron-stained quartz mineral

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

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Quartz with Muscovite Mica

Silicon Dioxide (SiO2) with Potassium Aluminum Silicate Hydroxide Fluoride (KAl2(AlSi3O10)(F,OH)2)

Mixed beach-stone and tumbled-glass collection

Predominantly uncertain rocks (likely basalt, granite, and quartz-bearing stones) with anthropogenic glass; one possible banded agate or jasper

Slag

Anthropogenic Vitrophyre (Iron or Smelting Slag)

Black Obsidian

Amorphous volcanic glass (SiO2 + impurities)

Blue goldstone beads

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

Hematite

Iron(III) oxide (Fe2O3)

Slag (Industrial Byproduct)

Ferro-silicate glass (Slag)

Unidentified gray mineral/rock fragment

Indeterminate from image; possibly quartz-rich material or mica-bearing schist

Pumice (likely)

Vesicular volcanic glass, typically rhyolitic or dacitic in composition

Iron-rich concretion or slag-like mineral fragment

Likely limonite/goethite (FeO(OH)·nH₂O), possibly magnetite-bearing material

Diamond

Native Carbon (C)

Silicon Carbide (Carborundum)

Moissanite (SiC)

Baked-clay ceramic fragment (likely brick or pottery)

Fired clay, primarily aluminosilicate minerals; not a natural rock

Polished silver sheen obsidian heart

Obsidian (volcanic glass), primarily rhyolitic silica-rich glass

Slag

Ferrous Slag (Siliceous industrial waste)

Slate

Slate (foliated metamorphic rock)

Chert (Arrowhead Fragment)

Microcrystalline Quartz (SiO2)

Green Slag Glass

Amorphous Silicon Dioxide (with metallic impurities)