Man Made Composite

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Diamond

C (Native Carbon)

Diamond (Cut Gemstone)

Natural Carbon (C)

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Quartz (Microcrystalline/Chert)

Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 principal)

Vesicular volcanic rock, likely weathered pumice or scoria

Pumice/scoria; predominantly volcanic glass and feldspar, with possible iron oxides

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pearls (likely freshwater cultured pearls)

Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin

Turquoise

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

Pearl (Biogenic Mineraloid)

Calcium carbonate (Aragonite) and Conchiolin, CaCO3

Tumbled greenstone (likely serpentinite or green jasper)

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

Carved serpentine pendant

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

Chert (Flint)

Chert (Cryptocrystalline Quartz, SiO2)

Sandstone

Sandstone (clastic sedimentary rock, composed predominantly of sand-sized minerals or rock fragments)

Chert (variations include Flint/Novaculite)

Chert (formula: SiO2)

Chert (often called Flint for darker varieties)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Flint

Silicon Dioxide (SiO2) - Chert variety

Coquina / Fossiliferous Limestone

Fossiliferous Limestone (Calcite, CaCO3)

Mixed stone-bead bracelet, likely agate/jasper and possibly sodalite or dyed quartz

Primarily microcrystalline quartz (SiO₂) varieties, with opaque iron-rich chalcedony/jasper and probable blue sodalite or dyed material

Tumbled chalcedony or quartz fragment

Microcrystalline quartz, SiO₂ (probable chalcedony)

Granite Pebble

Granite

Granodiorite with Quartz Veining

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

Limestone

Calcium Carbonate (CaCO3)

Polished serpentine pendulum

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

Granite

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

Diamond ring

Diamond, crystalline carbon (C)

Rough Diamond

Diamond (Pure Carbon: C)

Diamond

Carbon (C)

Pyrite

Iron Disulfide (FeS2)

Polished dendritic agate cabochon (likely agate or jasper)

Microcrystalline quartz, SiO₂, commonly chalcedony with iron-oxide inclusions

Quartzite

Quartzite (SiO2)

Polished black stone, likely black tourmaline or black obsidian

Most consistent with schorl tourmaline (NaFe3Al6(BO3)3Si6O18(OH)4), though black obsidian (volcanic glass) is also possible

Tumbled quartz-rich stone, possibly milky quartz or quartzite

Quartz (SiO₂), potentially quartzite if metamorphic

Loose faceted colorless gemstones, likely quartz or glass-like mineral chips

Most consistent with quartz (SiO₂), though the photograph cannot exclude synthetic cubic zirconia or glass

Vesicular Rhyolite

Rhyolite (High-silica volcanic rock)

Diamond

Carbon (C)

Diamond

Diamond (pure 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)

Polished malachite

Malachite (Cu₂CO₃(OH)₂), a hydrated copper carbonate hydroxide

Diamond

Carbon (C)

Faceted gemstone in a jewelry setting

Indeterminate from image; likely quartz, cubic zirconia, or another transparent faceted stone