Man Made Material

Petrified wood

Silicified wood, commonly quartz/chalcedony (SiO₂) replacing wood tissue

Green Fluorite

Fluorite (Calcium Fluoride - CaF2)

Polished turquoise

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

Schist

Mica Schist (Medium-grade metamorphic rock)

Milky Quartz

Silicon Dioxide (SiO2)

Likely galena-bearing ore

Galena (PbS), possibly mixed with quartz or carbonate gangue

Plume Agate or Moss Agate

Agate (SiO2)

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)

Ironstone Concretion / Goethite-Hematite Nodule

Goethite/Hematite (α-FeO(OH) / Fe2O3)

Orange Quartzite (River Pebble)

Quartzite (SiO2 with iron oxide impurities)

Limestone

Sedimentary rock composed mainly of calcium carbonate (CaCO3)

Chert (Quartz)

Microcrystalline Silica (SiO2)

Tumbled dark green stone, likely serpentine or greenstone

Serpentinite (hydrated magnesium silicate minerals, chiefly antigorite/lizardite); possible chlorite-rich greenstone

Milky Quartz with inclusions

Silicon Dioxide (SiO2)

Turquoise cabochon

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

Petrified Wood

Silicified wood (SiO2)

Chert (Flint)

Chert (SiO2)

Puddingstone (Quartzite Conglomerate with Jasper inclusions)

Metaconglomerate (Silicon Dioxide, SiO2)

Red Jasper

Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Blue calcite (probable)

Calcite, CaCO₃

Chert / Flint Nodule

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Polished serpentine

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

Milky Quartz Pebble (Iron-stained)

Silicon Dioxide (SiO2)

Granite with Epidote

Granite, containing quartz, feldspar, and epidote

Petrified Wood

Silicified Wood (SiO2)

Calcite crystal cluster (dogtooth/saddle calcite)

Calcite — calcium carbonate, CaCO₃

Limestone

Sedimentary rock composed primarily of calcium carbonate (CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

Quartzite

Quartzite (SiO2)

Limestone Pebble

Sedimentary Calcium Carbonate (CaCO3)

Sandstone

Arenite

Banded Calcite

Calcite (Calcium Carbonate, CaCO3)

Sandstone

Arenite (SiO2 with various cementation agents)

Limestone

Calcium Carbonate (CaCO3)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Sandstone Clast

Arenite (primarily SiO2)

Plagioclase Feldspar

NaAlSi3O8 – CaAlSi2O8 (Sodium-Calcium Aluminum Silicates)

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Iron Oxide cement)

Quartz Pebble

Silicon Dioxide (SiO2)

White Quartz Pebble

Silicon Dioxide (SiO2)

Quartzite

Quartzite (SiO2)

Sandstone

Arenite (composed primarily of SiO2)