Antropogenic (Man Made)

Diamond-set letter “L” jewelry piece

Diamond (crystalline carbon, C) set in a metal mount; the metal is not identifiable from the image

Green-and-white terrazzo (likely serpentine/marble aggregate)

Composite decorative stone; probable serpentinite (Mg₃Si₂O₅(OH)₄) with white calcite marble fragments in cementitious matrix

Chert (Chocolate or Brown Flint)

Chert (SiO2)

Diamond

Natural Diamond (Carbon, C)

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Diamond

C (Native Carbon)

Flaked stone projectile point

Likely worked chert or fine-grained silicified shale; exact lithology cannot be confirmed from the image

Conglomeratic concrete or asphalt aggregate surface with dark bituminous chunks

Polymictic gravel aggregate; dark pieces likely bitumen/asphalt, not a natural rock

Iron-stained chert (flint) nodule

Microcrystalline quartz (SiO₂), with iron-oxide staining

Chert (Flint/Chalcedony)

Silicon Dioxide (SiO2)

Sandstone (Red/Brown Variety)

Arenite (composed primarily of SiO2 with Fe2O3 iron oxide inclusions)

Sandstone

Arenite (SiO2 principal)

Pearls (likely freshwater cultured pearls)

Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin

Stamped concrete made to resemble flagstone

Portland-cement concrete with decorative stone-textured finish

Tumbled greenstone (likely serpentinite or green jasper)

Serpentinite, commonly dominated by serpentine-group minerals (Mg₃Si₂O₅(OH)₄); exact identification requires testing

Quartzite

Metamorphic Quartzite (SiO2)

Pyrite

Iron Sulfide (FeS2)

Concrete-like aggregate surface with embedded rock fragments

Anthropogenic concrete or exposed aggregate; not a natural rock specimen

Red gemstone ring, likely garnet or synthetic ruby

Possibly almandine garnet (Fe₃Al₂(SiO₄)₃) or corundum/ruby (Al₂O₃); image alone cannot distinguish

Diamond (or Diamond Simulant)

Carbon (C)

Green Slag Glass

Amorphous Silica / Glassy Blast Furnace Slag

Rounded quartz pebble

Quartz (silicon dioxide, SiO₂)

Tumbled obsidian

Volcanic glass; chiefly SiO₂, noncrystalline

Diamond (Cut Gemstone)

Natural Carbon (C)

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Swirled Agate Bead

Silicon Dioxide (SiO2)

Quartz (Microcrystalline/Chert)

Silicon Dioxide (SiO2)

Carved serpentine pendant

Serpentine-group minerals, commonly antigorite/lizardite (Mg₃Si₂O₅(OH)₄), possibly mixed with chlorite or other inclusions

Granodiorite with Quartz Veining

Granodiorite (containing Plagioclase Feldspar, Quartz, and Biotite/Hornblende) with Quartz (SiO2) veins

Flint

Silicon Dioxide (SiO2) - Chert variety

Coquina / Fossiliferous Limestone

Fossiliferous Limestone (Calcite, CaCO3)

Polished serpentine pendulum

Serpentine-group minerals, chiefly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pearl (Biogenic Mineraloid)

Calcium carbonate (Aragonite) and Conchiolin, CaCO3

Granite

Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Chert (variations include Flint/Novaculite)

Chert (formula: SiO2)

Chert (often called Flint for darker varieties)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Diamond

Carbon (C)

Pyrite

Iron Disulfide (FeS2)

Diamond ring

Diamond, crystalline carbon (C)

Lapis lazuli and green-blue chalcedony jewelry

Lapis lazuli: lazurite-bearing metamorphic rock, chiefly lazurite (Na₃Ca(Al₃Si₃O₁₂)S) with calcite and pyrite; second stone: likely chrysoprase or green-blue chalcedony (microcrystalline quartz, SiO₂)