Man Made Rock Like Material

Chert (and/or Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Geode (Unopened)

Quartz Geode (SiO2) / Chalcedony Concretion

Diamond in Kimberlite

Diamond (C in Kimberlite Matrix)

Tumbled greenstone (likely serpentinite or green jasper)

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

Brecciated jasper (likely red-and-cream jasper)

Jasper, an opaque microcrystalline variety of quartz; primarily cryptocrystalline SiO₂ with iron-oxide staining and possible chalcedony/quartz veining

Diamond

Carbon (C)

Fossilized Shark Tooth

Carcharocles sp. or Striatolamia sp. (Phosphate/Carbonate mineralized Hydroxyapatite)

Black-and-white agate or onyx bead necklace

Variegated chalcedony (microcrystalline SiO₂), possibly black-and-white banded agate; some black beads may be dyed chalcedony or hematite

Faceted gemstone in a jewelry setting

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

Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')

Calcite (Calcium Carbonate, CaCO3)

Slag Glass (Cullet)

Amorphous Silica / Glass residue

Sandstone

Sandstone (SiO2-rich clastic sedimentary rock)

Yellow Sapphire (Raw)

Corundum (Al2O3)

Chert (Flint)

Chert (SiO2)

Vesicular basalt (possibly slag-contaminated)

Basalt; chiefly plagioclase and pyroxene, with possible olivine and secondary minerals

Diamond (in jewelry setting)

Diamond (C - Carbon)

Corundum (Pink Sapphire / Ruby)

Al2O3 (Aluminum Oxide)

Coquina

Biogenic Limestone (Coquina)

Chert (Arrowhead Shard)

Microcrystalline silica (SiO2)

Chert (varieties include Flint and Mudstone)

Microcrystalline Silica (SiO2)

Granite, possibly granodiorite

Coarse-grained felsic plutonic rock; chiefly quartz (SiO₂), potassium feldspar and plagioclase feldspar, with biotite and/or hornblende

Man-made Jewelry Charm (Enameled Metal)

Not a natural mineral; composed of base metal alloy (likely zinc or brass) and epoxy resin/enamel.

Diamond

Native Carbon (C)

Diorite

Phaneritic Intrusive Igneous Rock (composed of Plagioclase feldspar, Hornblende, and Biotite)

Chert (Nodule)

Chert (SiO2)

Blue Slag Glass

Amorphous Silica (Byproduct of smelting)

Slag Glass (Cullet)

Amorphous Silicon Dioxide (SiO2) with metal oxide colorants

Lava Rock (Dyed)

Basalt / Volcanic scoria

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Quartzite

Metamorphic Quartzite (SiO2)

Beaded blue-and-green gemstone jewelry

Likely dyed or treated chalcedony/agate and green aventurine or glass-like stone; exact identification requires testing

Pumice

Pumice (Vitreous volcanic rock)

Hoodoo (Limestone / Siltstone Formation)

Claron Formation (Sedimentary Rock - Limestone, Mudstone, Dolomite)

Desert Rose (also known as Sand Rose)

Gypsum (CaSO4·2H2O) or Barite (BaSO4) with sand inclusions

Flint (chert)

Microcrystalline quartz (SiO₂), a variety of chert

Chalcanthite (Likely Synthetic/Lab-Grown)

Hydrated copper(II) sulfate (CuSO4·5H2O)

Coquina

Biogenic Limestone (Calcite/Aragonite base, CaCO3)

Moissanite

Silicon Carbide (SiC)

Gold (Elemental Metal)

Gold (Au)

Chert (often called Flint for darker varieties)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (and Flint)

Silicon Dioxide (SiO2)

Rough Corundum (Sapphire/Ruby mixture)

Corundum (Aluminum Oxide, Al2O3)