Mineraloid (Synthetic)

Faceted purple gemstone, possibly amethyst

Likely quartz (SiO₂), variety amethyst; identification is uncertain from the image

Dyed Alum or Dyed Quartz (Ornamental Crystal)

Silicon Dioxide (SiO2) or Potassium Alum [KAl(SO4)2·12H2O]

Green gemstone ring, possibly emerald

The green stone may be emerald (beryl, Be₃Al₂Si₆O₁₈), but the photo cannot confirm its identity; the setting appears to be silver-colored metal.

Red cut gemstone, likely synthetic ruby

Corundum (Al₂O₃); possibly lab-grown ruby or red glass imitation

Opal

Hydrated Amorphous Silica (SiO2·nH2O)

Pearl

Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3

Faceted blue gemstone, likely blue topaz or synthetic spinel

Topaz (Al₂SiO₄(F,OH)₂) or synthetic spinel (MgAl₂O₄); image insufficient for certainty

Parti Sapphire

Corundum (Al2O3)

Polished mahogany obsidian

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

Polished mahogany obsidian

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

Polished black obsidian

Volcanic glass; predominantly rhyolitic silica glass (approximately 70–80% SiO₂)

Black Obsidian

Volcanic Glass (SiO2)

Black Obsidian

Volcanic Glass (Amorphous Silicon Dioxide)

Snowflake Obsidian

Volcanic glass containing Spherulitic Cristobalite (SiO2)

Obsidian

Volcanic Glass (70-75% SiO2)

Mahogany Obsidian

Volcanic Glass with Hematite inclusions (SiO2 + Fe2O3)

Opal

Hydrated Silica (SiO2·nH2O)

Gold Sheen Obsidian

Obsidian (volcanic glass with SiO2 + gas inclusions)

Limonite (Iron Ore)

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

Obsidian

Volcanic Glass (SiO2)

Obsidian

Volcanic Glass (SiO2)

White Precious Opal

Hydrated Silica (SiO2·nH2O)

Limonite (Hydrated Iron Oxide / Bog Iron)

FeO(OH)·nH2O

Opalite

Synthesized glass / Silicon dioxide glass

Possible blue sapphire

Corundum (Al₂O₃), possibly blue sapphire

Black faceted gemstone, possibly black spinel or onyx

Undetermined; candidates include spinel (MgAl₂O₄) or chalcedony (SiO₂)

Iridescent polished gemstone, likely opal

Common or precious opal (hydrated amorphous silica, SiO₂·nH₂O), possibly synthetic or glass imitation

Ruby

Corundum (Al2O3)

Amber

Fossilized tree resin (Amorphous organic mineraloid)

Likely rough amber

Amber (fossilized tree resin; organic mineraloid)

Faceted clear gemstone in a gold-tone ring

Likely colorless quartz (SiO₂); the image does not establish the stone identity, and glass or another gem is possible

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Artificial Rock Face (Faux Rock)

Glass Fiber Reinforced Concrete (GFRC)

Pink-purple faceted gemstone ring (likely garnet)

Likely almandine–pyrope garnet, (Fe,Mg)₃Al₂(SiO₄)₃; identification from the image is uncertain.

Cubic Zirconia

Cubic Zirconium Dioxide (ZrO2)

Crackled Quartz (Dyed)

Silicon Dioxide (SiO2)

Black Opal Ring (Carved Opal)

Hydrated Silicon Dioxide (SiO2·nH2O)

Opal (Precious Opal)

Hydrated Silica (SiO2·nH2O)

Pearl

Aragonite / Calcium Carbonate (CaCO3)

Faceted black gemstone, likely black spinel

Spinel, MgAl₂O₄ (identification from appearance is uncertain)

Diamond

Natural Diamond (Carbon, C)

Diamond (Cut Gemstone)

Carbon (C)