Man Made Material, Not A Natural Rock Or Mineral Specimen

Faceted colorless gemstone, likely quartz (rock crystal)

Quartz, SiO₂

Diamond

Carbon (C)

Weathered quartz-bearing rock

Quartz-rich vein material; likely quartz with iron oxides and feldspar, exact rock type uncertain

Polished agate geode slice

Banded chalcedony (microcrystalline SiO₂), with druzy quartz and possible iron-oxide inclusions

Diamond

Carbon (C)

Gem-set gold ring

Unidentified transparent gemstone, possibly quartz or glass, set in a gold-colored metal ring

Polished white chalcedony or milky quartz pebble

Chalcedony, microcrystalline quartz (SiO₂), possibly with iron-oxide staining or a minor mineral inclusion

Clear quartz crystal (likely)

Quartz, silicon dioxide (SiO₂)

Limpets Shell / Fossil Specimen

Patellogastropoda (Class)

Sandstone

Sedimentary Rock (Quartz Sandstone)

Sandstone (Iron-stained)

Clastic sedimentary rock (SiO2 with Fe2O3 staining)

Iron-oxide-stained rock, likely limonite/goethite-bearing stone

Limonite (a mixture of hydrated iron oxides, commonly including goethite, FeO(OH)) coating or staining a host rock

Yellow Sapphire (Raw)

Corundum (Al2O3)

Amethyst cluster

Amethyst, purple quartz (SiO₂)

Fossilized shell

Indeterminate bivalve shell; likely calcitic or aragonitic shell material (CaCO₃)

Opalite

Man-made synthetic glass with opalescent effects (SiO2 + metal oxides)

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)

Amber cabochon pendant

Amber (fossilized plant resin), chiefly polymerized diterpenoid resin

Goldstone and pink quartz bead strands

Goldstone is aventurescent copper-bearing glass; pink beads are likely rose quartz (SiO₂), though dyed or glass imitations are possible

Exposed shoreline bedrock and sediment

Unidentified natural rock; the image does not show enough detail for a specific geological identification

Ferro-silicate Slag

Industrial Vitrified Slag (High-silica amorphous glass)

Granite

Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).

Sandstone

Sedimentary Clastic Rock

Carnelian cabochon pendant

Carnelian, orange-red chalcedony (microcrystalline quartz, SiO₂)

Sandstone (with potential Quartzite characteristics)

Clastic sedimentary rock (primarily SiO2)

Quartz Vein in Host Rock

Silicified matrix with hydrothermal quartz (SiO2)

Sandstone

Arenite (primarily SiO2)

Sandstone (Stream-rounded Cobble)

Arenite (composed primarily of SiO2, Silica)

Amethyst and aquamarine gemstone bracelet

Amethyst: purple quartz, SiO₂; blue beads likely aquamarine/blue quartz, with possible metallic spacer beads

Small metallic-looking rock fragment

Uncertain; possibly galena-bearing ore or mica-rich schist

Beaded gemstone jewelry (likely amethyst, lapis lazuli, and pearl or glass imitation)

Mixed mineral beads; possible quartz (SiO₂) and lazurite-bearing lapis lazuli

Blue stone cabochon, likely lapis lazuli or dyed stone

Lapis lazuli: lazurite-rich rock, chiefly (Na,Ca)₈(AlSiO₄)₆(S,SO)₂; exact identification is uncertain from the image

Diamond

Carbon (C)

Painted Rock / Geode Specimen

Silicon Dioxide with artificial pigment coating

Diamond (in a jewelry setting)

Cubic Carbon (C)

Terrazzo (with Marble and Granite fragments)

Cementitious or resinous composite containing Calcium Carbonate (CaCO3) and Silicates

Diamond (Cluster Ring)

Carbon (C)

Tumbled yellow-brown chalcedony (likely agate)

Microcrystalline quartz, SiO₂; chalcedony, possibly iron-stained agate

Turquoise cabochon

Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O

Sandstone

Arenite (primarily SiO2)

Shark Tooth Fossil

Vertebrate fossilized tooth

Sandstone (Ferruginous)

Arenite (SiO2 with Fe-oxide cement)