Mineraloid (Man Made)

Polished green serpentine

Serpentinite, chiefly antigorite/lizardite Mg₃Si₂O₅(OH)₄

Chert (specifically White Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Green iridescent glass cabochon or synthetic gemstone

Likely synthetic glass; possibly coated synthetic quartz or lab-created green gemstone

Native silver fragment (probable)

Silver, Ag; possibly silver-bearing sulfide or plated metal

Greenstone (probable altered basalt)

Chlorite–epidote–actinolite-rich greenschist; composition commonly derived from basalt

Pyrite-bearing quartz or sulfide-rich rock

Pyrite (FeS₂) in quartz-rich matrix, possibly with chalcopyrite

Iron-rich vesicular rock, possibly weathered scoria or ironstone

Likely oxidized basaltic scoria (Fe-oxide-bearing volcanic rock); exact identification requires testing

Pallasite Meteorite

Pallasite (Stony-Iron Meteorite)

Red Sandstone

Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)

Diamond

Carbon (C)

Dumortierite in Quartz

Dumortierite (Al6O3(BO3)(SiO4)3) with Quartz (SiO2)

Flint

Silicon dioxide (SiO2)

Likely gold-colored metal ring with a possible gemstone

Uncertain; possibly gold alloy (Au) with a small quartz or glass-like setting

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Quartzite

Quartzite (SiO2)

Diamond

Carbon (C)

Pearl (with Peridot)

Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4

Greenstone / serpentinite carving

Serpentinite, chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile); exact identification requires testing

Chert (varieties: Flint or Jasper)

Silicon dioxide (SiO2) / Microcrystalline Quartz

Diamond (Faceted)

Carbon (C)

Raw Diamond

Carbon (C)

Diamond (in jewelry setting)

Adamantine Carbon (C)

Chert (Chocolate or Brown Flint)

Chert (SiO2)

Sandstone Concretion

Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)

Chert (Flint/Chalcedony)

Silicon Dioxide (SiO2)

Sandstone (Red/Brown Variety)

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

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

Quartzite

Metamorphic Quartzite (SiO2)

Pyrite

Iron Sulfide (FeS2)

Diamond

Natural Diamond (Carbon, C)

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Diamond

C (Native Carbon)

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

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

Tumbled green jasper or serpentine

Jasper: microcrystalline quartz (SiO₂); possible serpentine: Mg₃Si₂O₅(OH)₄

Tumbled orange chalcedony and a gray stone disk

Chalcedony (microcrystalline quartz, SiO₂); disk likely fine-grained sandstone or slate

Diamond (or Diamond Simulant)

Carbon (C)

Sandstone

Arenite (SiO2 principal)

Rounded quartz pebble

Quartz (silicon dioxide, SiO₂)

Diamond (Cut Gemstone)

Natural Carbon (C)

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Pearls (likely freshwater cultured pearls)

Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin