Synthetic Polymer (Polylactic Acid)

Pink Cubic Zirconia (CZ)

Zirconium Dioxide (ZrO2)

Chalcanthite (Likely Synthetic/Lab-Grown)

Hydrated copper(II) sulfate (CuSO4·5H2O)

Limestone

Calcium Carbonate (CaCO3)

Green Calcite

Calcium Carbonate (CaCO3)

Fossilized coral or carbonate fossil fragment

Calcareous fossil, likely colonial coral (order Hexacorallia; uncertain from image)

Rough Diamond (Uncut Diamond)

Native Carbon (C)

Limestone

Carbonate rock (CaCO3)

Green Calcite

Calcium Carbonate (CaCO3)

Sapphire (likely blue synthetic sapphire or blue glass in a ring)

Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.

Amber

(C10H16O)n – an amorphous organic substance, primarily composed of polymerized isoprenoids.

Corundum

Corundum (Al2O3)

Emerald

Beryl (Be3Al2Si6O18), specifically the green variety colored by chromium or vanadium

White Marble

Metamorphic carbonate rock (primarily CaCO3)

Translucent amber-colored gemstone, likely citrine or amber

Most plausibly quartz (SiO₂), specifically citrine; amber would be fossilized resin (organic polymer)

Diamond

Carbon (C), Native Element

Tumbled pale limestone or calcite-rich stone

Limestone, chiefly calcite (CaCO₃); exact identification is uncertain from the photograph

Blue Calcite

Calcium Carbonate (CaCO3)

Crushed Limestone and Calcite

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Possible pink calcite or quartz-rich mineral specimen

Tentatively calcite (CaCO₃), possibly with iron-oxide staining; identification is uncertain from the image

Orange Calcite

Calcium Carbonate (CaCO3)

Pink Calcite

Calcium Carbonate (CaCO3)

Polished blue chalcedony or glass-like quartz specimen

Chalcedony (microcrystalline SiO₂), possibly treated or synthetic; exact identification requires testing

Colorless faceted gemstone (most likely synthetic cubic zirconia)

Cubic zirconia, ZrO₂ (likely synthetic); natural alternatives include quartz or diamond

Green Calcite

Calcium Carbonate (CaCO3)

Quartzite

Quartzite (SiO2)

Marble

Metamorphosed Limestone (CaCO3)

Blue chalcedony cabochon (probable)

Chalcedony, cryptocrystalline quartz; silicon dioxide (SiO₂)

Goldstone (aventurine glass)

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

Lapis Lazuli

Lapis Lazuli (a rock composed primarily of Lazurite (Na,Ca)₈[(S,Cl,SO₄,OH)₂|(Al₆Si₆O₂₄)], with varying amounts of Calcite, Pyrite, and Sodalite.)

Opal

Hydrous silicon dioxide (SiO2·nH2O)

Tumbled cream-colored stone, likely quartzite or limestone

Probably quartzite (microcrystalline SiO₂); limestone alternative: calcite (CaCO₃)

Limestone

Calcium Carbonate (CaCO3)

Calcite on Limestone (or Fossil)

Calcium Carbonate (CaCO3)

Amber

Fossilized tree resin (not a true mineral as it is organic and amorphous); Chemical formula is highly variable, but often approximated as C10H16O.

Amber

Succinite (specifically for Baltic amber; general formula C10H16O)

Blue aragonite (probable)

Aragonite, CaCO₃; blue color likely from copper-bearing impurities

Tumbled honey calcite (likely)

Calcite, calcium carbonate (CaCO₃)

Polished fossiliferous limestone pebble

Fossiliferous micritic limestone, probably containing gastropod or bivalve fragments

Gray Limestone

Calcite-rich Sedimentary Rock (CaCO3)

Limestone

Sedimentary rock composed mainly of calcium carbonate (CaCO3)

Limestone Cobble

Sedimentary Limestone (Calcium Carbonate, CaCO3)