Man Made Material

Diamond

Native Carbon (C)

Coquina

Biogenic Limestone (Coquina)

Green Quartzite

Metamorphic Quartzite (often colored by chromium-bearing minerals or fuchsite)

Sandstone

Arenite (composed primarily of SiO2)

Slag (Industrial Glass/Metal)

Ferrous slag or Glassy silicate byproduct

Likely tumbled epidote-bearing rock or green jasper

Epidote-group silicate, possibly in a jasper or serpentinite matrix

Goldstone

N/A (Synthetic Glass with Copper Inclusions)

Sunstone (Aventurine Feldspar)

(Ca,Na)((Al,Si)2Si2O8) with inclusions of Cu or Fe2O3

Turquoise cabochon ring

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Beaded blue-and-green gemstone jewelry

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

Polished greenstone pebble

Likely nephrite jade (tremolite–actinolite), though serpentine or greenstone is possible from appearance alone

Concrete or asphalt-like aggregate surface with a dark fragment

Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock

Unknown dark mineral/rock fragment

Indeterminate; possibly a dark sulfide mineral or slag-like geological fragment

Banded agate cabochon

Microcrystalline quartz (chalcedony), SiO₂

Iron-stained quartz-rich rock, possibly jasper or chert

Microcrystalline quartz (SiO₂) with iron oxides/hydroxides

Chert (with nodule)

Microcrystalline Quartz (SiO2)

Quartzite

Metamorphic Quartzite (SiO2)

Conglomeratic concrete or asphalt aggregate surface with dark bituminous chunks

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Aquamarine-like beryl pendant

Beryl, Be₃Al₂Si₆O₁₈; the beads may be dyed or treated chalcedony/amazonite, so image-only identification is uncertain

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

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

Polished black stone pendant

Likely black obsidian or black tourmaline; exact identification is uncertain from the photograph

Chert / Flint

Silicon Dioxide (SiO2)

Pearl and Garnet Glass

Calcium Carbonate (CaCO3) for pearl; Silicon Dioxide (SiO2) for glass

Flint

Silicon dioxide (SiO2)

Chert

Microcrystalline Silicon Dioxide (SiO2)

Quartz (Microcrystalline/Chert)

Silicon Dioxide (SiO2)

Chert (Flint)

Silicon dioxide (SiO2)

Turquoise-style beaded bracelet

Turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O; possibly dyed or composite beads

Chert Nodule

Microcrystalline Quartz

Chert (often called Flint or Jasper if reddish)

Microcrystalline Quartz (SiO2)

Coquina

Coquina (Biogenic Limestone / CaCO3)

Tektite

Natural impact glass

Chert / Flint

Silicon Dioxide (SiO2)

Turquoise bead bracelet

Turquoise — hydrated copper aluminum phosphate, CuAl₆(PO₄)₄(OH)₈·4H₂O

Multicolored beryl gemstone bracelet

Beryl, Be₃Al₂Si₆O₁₈; likely mixed aquamarine, morganite, heliodor, and green beryl beads

Sandstone

Arenite (composed primarily of SiO2)

Sandstone

Sandstone (Quartz-rich Arenite / SiO2)

Sandstone (with potential Arkose/Lithic characteristics)

Arenite (Sedimentary rock composed of sand-sized grains)

Tumbled yellow jasper or chalcedony

Microcrystalline quartz, SiO₂; likely iron-oxide-bearing jasper/chalcedony

Chalk

Carbonate rock (mainly CaCO3)

Chalk

Calcite (CaCO3)