Anthropogenic Material (Man Made Rock)

Mother of Pearl (Nacre)

Calcium Carbonate (primarily aragonite, with conchiolin)

Blue chalcedony cabochon (probable)

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

Polished stromatolite (likely fossilized microbial mat)

Fossil stromatolite; chiefly microcrystalline quartz (SiO₂), commonly replacing carbonate

Quartzite Arrowhead (Archaeological Lithic)

Recrystallized Quartz (SiO2)

Granite

Plutonic Igneous Rock (composed typically of SiO2, Al2O3, K2O, Na2O, CaO)

Red-and-brown agate bead bracelet

Agate, a microcrystalline variety of quartz (SiO₂), likely colored chalcedony/carnelian

Malachite

Malachite, Cu₂CO₃(OH)₂; a banded botryoidal copper carbonate specimen

Chert (varietal: Flint/Jasper)

Silicon Dioxide (SiO2)

Red Slag Glass (Cullet)

Amorphous Silicon Dioxide (SiO2) with metallic dopants

White-and-dark marble or agate-style gemstone bead bracelet

Likely calcite-rich marble (CaCO₃) mixed with dark gray stone beads; exact material is uncertain from the photo

Mixed quartz gemstone bead bracelet

Quartz, silicon dioxide (SiO₂), in varieties including smoky quartz, amethyst, rutilated quartz, and possibly tourmalinated quartz

Fossil coral in limestone

Fossilized colonial coral, likely tabulate or favositid coral (CaCO₃), preserved in calcitic limestone

Coal (Bituminous Coal)

Caustobiolith / Sedimentary Rock

Tumbled fossil shark tooth pendant

Likely fossilized shark tooth, possibly Otodus or Carcharhinus; exact species cannot be confirmed from the image

Grey Chalcedony

Silicon Dioxide (SiO2)

Gemstone ring (stones not reliably identifiable from the image)

Likely faceted yellow stones and clear stones set in a metal band; species and treatments are indeterminate visually

Goldstone

Avventurina (Cu + SiO2 glass)

Diamond

Native Carbon (C)

Diamond

Carbon (C)

Chert (Yellow Jasper/Flint)

Silicon Dioxide (SiO2)

Tumbled chalcedony (likely moss or dendritic agate)

Microcrystalline quartz, SiO₂, with iron-oxide inclusions

Chert (Flint)

Silicon Dioxide (SiO2)

Chert

Chert (SiO2)

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Silicon Dioxide (SiO2) with artificial coloration

Granite

Granite (composed primarily of Quartz, Feldspar, and Mica)

Yellow faceted gemstone, likely citrine or yellow sapphire

Uncertain; probable quartz (SiO₂) or corundum (Al₂O₃)

Goldstone (aventurine glass)

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

Pumice

Pumice (Vesicular volcanic glass)

Tumbled cream-colored pebble

Likely quartz-rich sandstone or limestone; exact identification requires testing

Desert Rose (Gypsum Rose)

Calcium Sulfate Dihydrate (CaSO4·2H2O)

Chert / Flint

Silicon Dioxide (SiO2)

Turquoise

Hydrated phosphate of copper and aluminum, CuAl6(PO4)4(OH)8·4H2O

Granite

Granite (felsic intrusive igneous rock)

Blue chalcedony cabochon (likely)

Chalcedony, microcrystalline SiO₂; possibly blue agate or common opal, which cannot be distinguished confidently from the image

Blue Lace Agate

Chalcedony (SiO2) with trace inclusions

Turquoise ring

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; the setting appears to be silver-colored metal

Clay (as a rock-forming material)

Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)

Sandstone

Arenite

Iron-rich vesicular rock, possibly slag or weathered basalt

Identification uncertain; likely ferruginous basalt/ironstone, with possible anthropogenic iron slag

Polished blue-green glassy slag or coated mineral fragment

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

Diamond

Carbon (C)