Mineraloid (Man Made Glass)

Black obsidian

Volcanic glass; predominantly rhyolitic silica-rich melt (approximately 70–80% SiO₂), lacking crystalline structure

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Limonite or Ironstone Nodule

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Obsidian

Volcanic Glass (Amorphous SiO2)

Likely green bottle glass, not a geological specimen

Manufactured soda-lime silicate glass

Snowflake Obsidian

Volcanic Glass with Spherulite inclusions (Chemical composition: 70–75% SiO2 + MgO, Fe3O4)

Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Likely obsidian fragment

Volcanic glass, predominantly silica-rich rhyolitic composition (SiO₂-rich)

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

Amber

Succinite (with a generalized formula of C10H16O)

Red cabochon gemstone ring (likely glass or synthetic stone)

Undetermined; the image does not establish a natural mineral identity

Obsidian

Volcanic glass (Amorphous silicon dioxide)

Corundum (Pink Sapphire / Ruby)

Al2O3 (Aluminum Oxide)

Blue tumbled glass or dyed stone (uncertain)

Unidentified; appearance is consistent with blue glass, but a blue mineral such as dyed quartz cannot be ruled out from the photo

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)

Chert (flint), likely a weathered nodule fragment

Microcrystalline quartz (SiO₂), commonly termed chert or flint

Polished mahogany obsidian

Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–75% SiO₂)

Sea Glass

Amorphous silicon dioxide (glass)

Obsidian (likely black obsidian)

Volcanic glass, predominantly rhyolitic to dacitic silica-rich melt; approximate composition ~70–75% SiO₂

Obsidian

Volcanic Glass (predominantly SiO2, approximately 70% or more)

Green Aventurine

Quartz (SiO2) with Fuchsite inclusions

Rough Diamond

Native Carbon (C)

Likely obsidian (rough fragment)

Volcanic glass, predominantly silica-rich rhyolitic composition (SiO₂-rich, noncrystalline)

Tumbled quartz (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Obsidian (black volcanic glass)

Obsidian; predominantly rhyolitic volcanic glass, mainly SiO₂ with minor feldspar, quartz, and iron oxides

Milky quartz

Quartz (silicon dioxide, SiO₂)

Mahogany Obsidian

Volcanic glass (SiO2 + Fe2O3)

Colorless faceted gemstone, likely glass or quartz

Uncertain; possibly quartz (SiO₂), but the strong uniform brilliance and apparent molded/faceted form may indicate leaded glass or cubic zirconia

Brown chert (flint)

Microcrystalline quartz (SiO₂), commonly called chert; “flint” is a dark variety

Golden Sheen Obsidian

Volcanic Glass (predominantly SiO2, >70%)

Mahogany Obsidian

Obsidian (volcanic glass with hematite/magnetite inclusions)

Black Opal (Triplet)

Hydrated Silica (SiO2·nH2O)

Likely clear quartz crystal (possibly cut/polished quartz or glass imitation)

Quartz, silicon dioxide (SiO₂)

Metal Chain (Likely Steel or a Steel Alloy)

Steel (primarily iron and carbon); specific alloy unknown

Limonite (Iron Ore)

Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)

Black Obsidian

Volcanic glass (Amorphous silicates)

Small yellow-orange mineral fragment, likely amber or iron-stained quartz

Possibly amber (fossilized resin; organic mineraloid) or quartz (SiO₂)

Faceted clear gemstone ring, likely quartz or glass imitation

Unidentified colorless faceted material; quartz (SiO₂) is possible, but the image cannot distinguish it from glass or another gem

Milky quartz pebble

Quartz (silicon dioxide, SiO₂)

Obsidian

Volcanic Glass (comprised primarily of SiO2)

Limonite (Iron Ore)

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)