Sedimentary (Man Made)

Possible sea glass (naturally frosted glass), not a confirmed geological specimen

Man-made silicate glass; composition varies, commonly soda-lime glass

Blue glassy mineral specimen, possibly dyed or synthetic

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

Black beaded bracelet, likely black onyx or glass

Possibly chalcedony (microcrystalline quartz, SiO₂); the beads may instead be man-made glass

Opalite (a synthetic glass, often confused with Opal)

Silicon dioxide glass (SiO2nH2O, for natural opal)

Polished blue calcite sphere (tentative identification)

Calcite, CaCO₃; blue color generally results from trace impurities or inclusions

Chert (possibly a worked stone flake)

Microcrystalline quartz, SiO₂

N/A - Man-made object (Jewelry Chain)

Antiqued or Oxidized Metal Chain (often Steel or Brass)

Man-made Jewelry Charm (Enameled Metal)

Not a natural mineral; composed of base metal alloy (likely zinc or brass) and epoxy resin/enamel.

Cullet Glass (Man-made Glass Slag)

Amorphous Silica (SiO2) with chemical additives

Cobalt Glass Slug (Man-made Glass)

Amorphous Silica with Cobalt Oxide (SiO2 + CoO)

Man-made Metal Pin (Non-geological)

Antimony-Lead Alloy or Zinc/Brass Base with Electroplating

Red glassy cabochon, likely synthetic ruby or red glass

Uncertain; possible synthetic corundum (Al₂O₃, chromium-colored) or man-made glass

Tumbled opalite (likely synthetic glass)

Opalite; typically man-made opalescent soda-lime glass, not a recognized mineral species

Flint (chert)

Microcrystalline quartz (SiO₂), commonly called chert or flint

Blue Chalcedony Cube

Silicon Dioxide (SiO2)

Goldstone (Red/Brown)

Aventurine Glass (SiO2 with Copper inclusions)

Chert (flint), brown variety

Microcrystalline quartz (SiO₂)

Chalk

Micrite (primarily Calcium Carbonate, CaCO3)

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

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

Man-made Green Quartz (Lab-grown or Treated)

Silicon Dioxide (SiO2) with artificial coloration

Goldstone (blue/black aventurine glass)

Man-made aventurine glass; silica glass containing metallic copper or other glittering inclusions

Small clear crystal, possibly quartz or glass-like gemstone

Uncertain; likely quartz (SiO₂), but the image is insufficient to exclude man-made glass or cubic zirconia

Carnelian

SiO2 (variety of chalcedony)

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

Polished green-and-black banded cabochon (likely malachite imitation or dyed agate)

Uncertain; possible malachite (Cu₂CO₃(OH)₂), banded agate (SiO₂), or man-made glass

Green glass cabochon or tumbled stone

Indeterminate; likely man-made glass, possibly aventurine glass rather than a natural mineral

Polished blue-green glassy slag or coated mineral fragment

Most likely man-made colored glass/slag; exact composition cannot be determined visually

Blue goldstone beads

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

Small rounded pebble (rock type indeterminate)

Unidentified fine-grained lithic pebble

Flint (chert)

Microcrystalline quartz (SiO₂), a variety of chert

Tumbled sea glass or pale-green quartz pebble

Indeterminate from image; possibly quartz (SiO₂), but the smooth translucent piece may be man-made glass

Chalk

Calcium Carbonate (CaCO3)

Chert (likely flint)

Microcrystalline quartz, SiO₂

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

Colorless faceted quartz-like gemstone

Likely quartz (SiO₂), though the appearance may also indicate man-made glass or cubic zirconia

Chert

Chert (Microcrystalline Quartz)

Flint (chert)

Microcrystalline quartz (SiO₂), a variety of chert

Likely chert (flint)

Microcrystalline quartz (SiO₂), likely chert; exact identification is uncertain from the image alone

Chert (flint), likely a weathered nodule fragment

Microcrystalline quartz (SiO₂), commonly termed chert or flint

Possible ironstone concretion or weathered mineral nodule

Iron-oxide-rich concretion, likely goethite/limonite; identification uncertain from the photo

Flint (chert)

Microcrystalline quartz, SiO₂

Blue chalcedony cabochon (probable)

Chalcedony, a cryptocrystalline variety of quartz; silicon dioxide, SiO₂