Manufactured Stone

Terracotta (Man-made ceramic brick fragment)

Baked clay / High-iron ceramic (Silicate-based ceramic)

Likely gold-colored metal ring with a possible gemstone

Uncertain; possibly gold alloy (Au) with a small quartz or glass-like setting

Blue glass-like gemstone specimen (likely dyed or synthetic quartz)

Uncertain; possibly blue-dyed quartz or synthetic glass, not confidently identifiable from the image

Black Opal (Triplet)

Hydrated Silica (SiO2·nH2O)

Goldstone (aventurine glass)

Synthetic copper-bearing soda-lime glass; commonly sold as red goldstone

Cubic Zirconia (Set in Jewelry)

Zirconium Dioxide (ZrO2)

Green glass-like cabochon, likely synthetic glass or resin

Unidentified green transparent material; possibly molded glass, synthetic spinel, or resin

White/green translucent tumbled mineral fragment

Likely calcite (CaCO₃), possibly fluorite (CaF₂) or glass-like feldspar; visual identification is uncertain

Cut quartz crystal (likely rock crystal)

Quartz, silicon dioxide (SiO₂), trigonal crystal system

Polished black obsidian

Volcanic glass; predominantly rhyolitic silica (SiO₂), with minor iron, magnesium, and alkalis

Leopard jasper (orbicular jasper)

Silicified volcanic rock, chiefly microcrystalline quartz/chalcedony (SiO₂) with feldspar and iron-oxide inclusions

Calcite (likely chalky calcite fragment)

Calcite, calcium carbonate (CaCO₃)

Likely silicon carbide (carborundum)

Synthetic silicon carbide (SiC), likely blue-green crystalline grit

Colorless faceted gemstone, likely glass or quartz

Uncertain; appearance is consistent with faceted quartz (SiO₂), but cut glass or cubic zirconia cannot be excluded from the photograph

Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)

N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)

Fossil ammonite fragment

Ammonoidea (likely a small heteromorph or coiled ammonite; exact genus indeterminate)

Opalite glass sphere (likely synthetic imitation)

Man-made opalescent glass; not natural opal

Possible iron-rich concretion or weathered ironstone

Goethite/hematite-bearing limonite concretion (tentative)

Likely obsidian (possibly tektite or slag glass)

Volcanic glass; primarily SiO₂, noncrystalline

Colorless faceted gemstone (likely cubic zirconia)

Cubic zirconia, zirconium dioxide (ZrO₂); possibly synthetic quartz or glass imitation

Black volcanic glass or basalt pendant

Likely basalt (fine-grained mafic rock), possibly obsidian (volcanic glass)

Blue-dyed tumbled quartz or glass imitation

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

Goldstone (likely red/brown aventurine glass)

Man-made aventurine glass; copper-bearing silicate glass (not a natural mineral)

Cobalt Blue Sea Glass

Amorphous Silica Glass (SiO2 + CoO)

Green glassy slag or manufactured glass bead

Noncrystalline silicate glass; likely industrial glass/slag, not a true mineral

Likely flint/chert fragments

Microcrystalline quartz (SiO₂), possibly fossil-bearing chert

Blue-dyed howlite beads (likely)

Howlite, Ca₂B₅SiO₉(OH)₅, commonly dyed blue to imitate turquoise

Wallboard/Drywall (Gypsum-based)

Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O

Quartz Pebble

Silicon Dioxide (SiO2)

Boxwork or Septarian Concretion

Septarian nodule / Boxwork weathering

Possible metallic meteorite or iron-nickel bead

Unconfirmed; possible Fe–Ni alloy (kamacite/taenite)

Opalite

Synthetic Opalite (Man-made glass)

Transit Token (RTD Denver)

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

3D Printed PLA Elephant (Silk Multi-color)

Polylactic Acid (C3H4O2)n

Goldstone (likely blue-free synthetic goldstone pendant)

Synthetic aventurine glass; silica glass with dispersed metallic copper crystals

Blue glassy fragment among beach gravel

Likely cobalt-blue man-made glass; not a natural mineral specimen

Sodium Polyacrylate (Superabsorbent Polymer)

Sodium Polyacrylate [-CH2-CH(COONa)-]n

Obsidian

Volcanic glass (SiO2-rich amorphous silicate)

Small gray rock fragment

Indeterminate; possibly quartz-rich granite, chert, or concrete-like silicate material

Synthetic Resin Charm (Seal Shape)

Polymer Resin with plastic glitter / Polyethylene terephthalate glitters

Colorless faceted gemstone, likely quartz (rock crystal)

Quartz, silicon dioxide (SiO₂); exact identification cannot be confirmed from the photograph

Magnetite-rich iron ore

Magnetite (Fe₃O₄), possibly mixed with hematite or metallic sulfides