Man Made Glass (Often Grouped With Minerals In Lapidary)

Chert (Chalky Flint Node)

Chert (Microcrystalline Quartz, SiO2)

Engineerged Quartz (Quartz Composite)

SiO2 (Silicon Dioxide) in a polymer resin matrix

Slag

Metallurgical by-product

Conglomerate

Conglomerate (Sedimentary rock containing rounded clasts)

Green sea glass (likely bottle glass)

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

Small greenish crystal/mineral fragment

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

Opalite

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

Decorative mosaic cross containing mixed rock and glass fragments

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

Goldstone (Brown/Gold variety)

Aventurine Glass (SiO2 with Copper inclusions)

Small rounded mineral pebble, possibly quartz

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

Blue glassy mineral specimen, possibly dyed or synthetic

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

Black glassy fragment, likely obsidian or industrial glass

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

Dalmatian Stone

Dalmatian Jasper (a misnomer for an Aplite with Arfvedsonite spots)

Green sea glass or tumbled green quartz (uncertain)

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

Crackle Agate / Dyed Quartz

SiO2 (Silicon Dioxide)

Diamond / Clear Quartz / Glass paste

Carbon (Diamond) / Silicon Dioxide (Quartz)

Green Slag Glass

Amorphous Silica / Glassy Blast Furnace Slag

Goldstone

Aventurine Glass (Man-made glass with copper inclusions)

Transit Token (RTD Denver)

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

Sandstone (with concrete/human-made layer)

Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)

Green Sea Glass

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

Cherry Quartz

SiO2 (Silicon Dioxide with iron-rich inclusions/dye)

Magnetic Hematite (Man-made)

Iron Oxide (Fe2O3) with Barium-Strontium Ferrite

Blue goldstone beads

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

Jasper / Chert (Red)

Cryptocrystalline quartz (SiO2)

Diamond (or Simulant)

Carbon (C)

Asphalt Concrete

Bituminous Concrete

Chert (Chalcedony/Agate variety)

Silicon Dioxide (SiO2)

Concrete

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

Polished black stone, likely black obsidian

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

Polished labradorite sphere

Labradorite, calcic plagioclase feldspar ((Ca,Na)(Al,Si)₄O₈)

Polished garnet bead bracelet

Garnet group, likely almandine–pyrope solid solution; commonly approximated as Fe₃Al₂(SiO₄)₃–Mg₃Al₂(SiO₄)₃

Slag Glass (Leland Blue variant)

Anthropogenic Vitreous Silicate

Titanium Coated Kyanite (Aura Kyanite)

Aluminosilicate (Al2SiO5) with a Titanium-Niobium vacuum-deposited coating

Opalite

Synthetic Fluorescent Glass (SiO2 + impurities)

Sea Glass

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

Concrete / Conglomerate (Man-made)

Artificial Conglomerate (Cementitious Composite)

Acrylic or Resin (Synthetic Imitation)

Polymethyl Methacrylate (PMMA) or Polyepoxide

Opalite (a synthetic glass, often confused with Opal)

Silicon dioxide glass (SiO2nH2O, for natural opal)

Titanium Aura Quartz (Bismuth-coated Druzy)

Silicon Dioxide (SiO2) with Titanium/Metal vapor coating

Tumbled jasper (likely yellow/brecciated jasper)

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

Concrete fragment with Aggregate

Anthropogenic Concrete with Calcarious and Siliceous Aggregate