Man Made Glass (Often Grouped With Minerals In Lapidary)

Black tumbled stone, possibly obsidian

Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image

Aura Quartz (Titanium/Rainbow Quartz)

SiO2 (Silicon Dioxide) with metallic coating

Slag

Glassy silicate byproduct (anthropogenic material)

Asphalt Concrete

Bituminous conglomerate

Opalite

Man-made synthetic glass with opalescent effects (SiO2 + metal oxides)

Sea Glass (specifically Frosted White)

Amorphous Silica (substance: Sodium-calcium silicate glass)

Green sea glass (likely bottle glass)

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

Concrete with Aggregate

Artificial Conglomerate (Cement and Aggregate)

Polymer Clay (Mock Mineral)

Polyvinyl chloride (PVC) with plasticizers and pigment

Clear quartz tumbled stone

Quartz (silicon dioxide, SiO₂)

Chert (Arrowhead/Artifact Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Moldavite

Tektite (Impact Glass), ~80% SiO2 + Al2O3

Goldstone

Aventurine Glass (Man-made glass with copper inclusions)

Green Sea Glass

Amorphous Silica (man-made glass), SiO2 + additive metal oxides

Sea Glass

Man-made vitreous material / Silicon dioxide

Blue goldstone beads

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

Engineerged Quartz (Quartz Composite)

SiO2 (Silicon Dioxide) in a polymer resin matrix

Green sea glass or tumbled green quartz (uncertain)

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

Aura Quartz Geodes (Lab-Altered)

Silicon Dioxide (SiO2) with Metallic Vapor Deposition

Chert (Chalky Flint Node)

Chert (Microcrystalline Quartz, SiO2)

Asphalt (Road Aggregate)

Bituminous conglomerate

Polished black pebble, likely basalt

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

Diamond / Clear Quartz / Glass paste

Carbon (Diamond) / Silicon Dioxide (Quartz)

Green Slag Glass

Amorphous Silica / Glassy Blast Furnace Slag

Blue glassy mineral specimen, possibly dyed or synthetic

Uncertain; possible blue fluorite (CaF₂), dyed chalcedony, or man-made glass

Blue cabochon, likely dyed or synthetic material

Undetermined; possibly dyed chalcedony (SiO₂), glass, or synthetic corundum

Diamond

Native Carbon (C)

Small greenish crystal/mineral fragment

Indeterminate; possibly olivine, quartz, or a green gemstone fragment

Black glassy fragment, likely obsidian or industrial glass

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

Conglomerate

Conglomerate (Sedimentary rock containing rounded clasts)

Jasper / Chert (Red)

Cryptocrystalline quartz (SiO2)

Goldstone (Brown/Gold variety)

Aventurine Glass (SiO2 with Copper inclusions)

Transit Token (RTD Denver)

Nickel-plated brass or bronze alloy (Cu-Sn-Zn-Ni)

Slag

Metallurgical by-product

Decorative mosaic cross containing mixed rock and glass fragments

Polychrome aggregate; likely quartz, feldspar, marble, granite, and assorted colored glass

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Small rounded mineral pebble, possibly quartz

Uncertain; likely microcrystalline or crystalline SiO₂ (quartz), potentially with iron-oxide staining

Sea Glass

Amorphous silicon dioxide (SiO2) - Man-made glass tumbled by nature

Polished black stone, likely black obsidian

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

Blue Goldstone

Synthetic glass with copper or cobalt/manganese inclusions

Green sea glass (likely)

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

Crackle Agate / Dyed Quartz

SiO2 (Silicon Dioxide)