Synthetic Glass (Man Made)

Concrete Rubble with Aggregate

Hardened Portland Cement Paste with Coarse Aggregate

Orgonite Pyramid (containing Amethyst and mixed minerals)

Silicon Dioxide (SiO2) in synthetic resin

Polished silver sheen obsidian heart

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

Green cabochon gemstone, likely aventurine or dyed chalcedony

Indeterminate from image; possible quartz variety (SiO₂), including aventurine quartz or chalcedony

Concrete

Anthropogenic Conglomerate

Colorless quartz crystal (likely quartz fragment)

Quartz, silicon dioxide (SiO₂)

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (Chert or Flint)

Jewelry Chain with Blue and Clear Gemstones (Likely Cubic Zirconia)

Cubic Zirconia (ZrO₂), Silver or White Gold/Platinum Alloy

Goldstone (likely blue-free synthetic goldstone pendant)

Synthetic aventurine glass; silica glass with dispersed metallic copper crystals

Amethyst gemstone ring

Quartz, purple variety — SiO₂

Blue Goldstone

Goldstone (artificial glass)

Strawberry Quartz

Silicon Dioxide (SiO2) with Hematite/Goethite inclusions

Aggregate Concrete

Anthropogenic Conglomerate (Technosol)

Asphalt Concrete

Bituminous Concrete

Titanium Aura Quartz

Titanium bonded Silicon Dioxide (SiO2 + Ti)

Sea Glass

Amorphous silicon dioxide (Man-made glass weathered by nature)

Chert Concretion

Chert (Microcrystalline Quartz, SiO2)

Blue Obsidian

Volcanic Glass (SiO2 with inclusions)

Aura Quartz (Titanium Quartz)

Titanium-coated Silicon Dioxide (SiO2 + Ti)

Concretion (Sandstone)

Carbonate-cemented Sandstone Concretion

Sea Glass

Amorphous Silicon Dioxide (Man-made glass weathered by nature)

Carved labradorite fish

Labradorite, calcium-rich plagioclase feldspar (approximately (Ca,Na)(Al,Si)₄O₈)

Polished brown jasper (likely brecciated or orbicular jasper)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions

Yellow faceted gemstone, likely citrine or synthetic glass

Citrine (quartz, SiO₂) is the leading natural possibility; visual identification is uncertain from the photograph

Black Obsidian

Amorphous volcanic glass (SiO2 + impurities)

Goldstone (brown goldstone)

Man-made aventurine glass, typically copper-bearing silica glass

Tumbled milky chalcedony (likely common opalite-like quartz)

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

Asphalt (Road Aggregate)

Asphalt concrete / Bituminous mixture

Aura Quartz

Titanium or Gold bonded Silicon Dioxide (SiO2)

Cullet (Slag Glass)

Amorphous Silica (Industrial byproduct)

Concrete with Aggregate

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

Green sea glass (likely)

Man-made glass, likely soda-lime silicate glass; not a natural mineral or rock

Iron Slag

Iron/Steel Slag (Ferrosilicate Glass)

Polished dendritic agate or jasper

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

Blue-dyed tumbled quartz or glass imitation

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

Possible obsidian or slag glass

Volcanic glass, primarily SiO₂; alternatively industrial iron-rich glassy slag

Glass / Silicon Dioxide (Man-made)

SiO2 (Amorphous Silicon Dioxide)

Concrete

Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)

Aura Quartz (specifically Titanium Aura Quartz)

Titanium-coated Silicon Dioxide (SiO2 + Ti Coating)

Blue glassy tumbled stone, likely blue chalcedony or slag glass

Chalcedony (microcrystalline SiO₂), possibly man-made blue glass

Quartz crystal (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Polished black stone, likely black obsidian

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