Man Made Composite

Tumbled green glassy mineral, possibly aventurine or fluorite

Uncertain; likely quartz variety (aventurine quartz, SiO₂) or green fluorite (CaF₂)

Chert (Arrowhead Shard)

Microcrystalline silica (SiO2)

Quartzite

Metamorphic Quartz Arenite

Likely clear quartz crystal (possibly cut/polished quartz or glass imitation)

Quartz, silicon dioxide (SiO₂)

Tourmalinated quartz point

Quartz (SiO₂) containing black tourmaline, usually schorl (NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)

Tumbled epidote-bearing rock (likely epidote–quartz–feldspar aggregate)

Epidote-rich metamorphic rock; minerals likely epidote (Ca₂(Al,Fe)₃Si₃O₁₂(OH), quartz, feldspar, and dark amphibole/biotite)

Chert (flint) fragment

Microcrystalline quartz (SiO₂), commonly called chert; “flint” is a variety of chert

Diamond

Diamond (Pure Carbon, C)

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Polished blue-green jasper beads

Jasper, an opaque microcrystalline variety of quartz (SiO₂)

Sandstone (likely Fossiliferous)

Arenite / Fossiliferous Sandstone (SiO2 composition)

Diamond-set gold ring

Diamond (carbon, C) in a gold alloy setting; the clear center stone may be a diamond or a diamond simulant

Gold ring with a clear faceted gemstone

Likely diamond (crystalline carbon, C); identification is uncertain from the image

Rounded granite cobble

Granite, a coarse-grained felsic intrusive igneous rock composed chiefly of quartz, feldspar, and mica

Diamond (Cluster Ring)

Carbon (C)

Diamond

Carbon (C)

Sandstone (with iron staining)

Quartz Arenite / Ferruginous Sandstone

Sandstone

Clastic Sedimentary Rock

Sandstone

Sedimentary Rock (Quartz arenite)

Quartzite

Quartzite (Metamorphic Quartz Sandstone)

Chert (Chert / Flint)

Microcrystalline Quartz (SiO2)

Diamond in Kimberlite

Diamond (C in Kimberlite Matrix)

Pearl

Calcium Carbonate (mostly Aragonite), CaCO3 (with conchiolin)

Rough Diamond

Diamond (pure Carbon, C)

Diamond

Native Carbon (C)

Diamond

Carbon (C)

Rough Diamond

Pure Carbon (C)

Fossilized Shark Tooth (Fragment)

Elasmobranchii gen. et sp. indet. (Calcium Phosphate / Apatite fossil)

Dark rounded pebble, likely basalt or slag

Probable fine-grained mafic rock; possibly basalt (plagioclase–pyroxene) or industrial iron/steel slag

Limestone

Calcium Carbonate (CaCO3)

Bituminous Coal (with Anthracite or Vitrinite inclusion)

Organic-rich Sedimentary Rock (Carboniferous classification)

Diamond ring

Diamond (crystalline carbon, C) set in a metal ring; the small stones appear diamond-like but cannot be confirmed from the image.

Diamond-set gold ring

Diamond (crystalline carbon, C) in a gold alloy setting

Gold ring with a clear faceted gemstone

Likely diamond (carbon, C); the photograph is insufficient to confirm the stone or metal

Mounted faceted gemstone ring

Likely diamond (carbon, C), though the image is insufficient for definitive identification

Likely blue glass or synthetic gemstone jewelry

Uncertain; possibly synthetic spinel, cubic zirconia, or blue glass

Limestone

Calcareous sedimentary rock (CaCO3)

Tree Agate

Chalcedony (SiO2)

Diamond (or Diamond Simulant)

Carbon (C)

Blue faceted gemstone ring, likely synthetic sapphire or blue topaz

Uncertain from image; possible corundum (Al₂O₃) or topaz (Al₂SiO₄(F,OH)₂)

Pumice

Vesicular volcanic glass, typically rhyolitic to dacitic; mainly silica-rich volcanic glass with feldspar and minor quartz or pyroxene

Polished malachite slab

Malachite, Cu₂CO₃(OH)₂; likely polished and possibly resin-stabilized