Mineral, Specifically A Cryptocrystalline Quartz Variety

Amethyst

Quartz variety; chemical formula: SiO₂ (silicon dioxide) with Fe³⁺ impurities

Jasper (likely river-worn)

Silicon Dioxide (SiO2)

Jasper (Iron-stained)

Jasper (Silicon Dioxide, SiO₂ with Iron inclusions)

Green Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Botryoidal Chalcedony (Desert Rose / Grape Agate variant)

Silicon Dioxide (SiO2)

Handaxe with Inlaid Fossil Echinoid

Flint / Chert (SiO2) containing a fossil Conulus albogalerus

Kambaba Jasper

Stromatolite (Fossilized Algae)

Chert (Chert / Flint)

Silicon Dioxide (SiO2)

Petrified Wood

Silicified wood (principally Silicon Dioxide, SiO2)

Green Jasper

Silicon Dioxide (SiO2) with impurities

Amethyst

SiO2 (Silicon Dioxide) - Purple variety of Crystalline Quartz

Rose Quartz

Silicon Dioxide (SiO2)

Red Jasper

Jasper (Silicon Dioxide with iron oxide inclusions), SiO2

Eagle Eye Stone (Green Tiger's Eye)

Pseudomorph of Quartz after Crocidolite (SiO2 with inclusions)

Beryl (Emerald Variety)

Beryllium Aluminum Silicate (Be3Al2(SiO3)6)

Petrified Wood

Silicified wood (primarily SiO2 - Silicon Dioxide/Quartz)

Baroque Pearl

Biogenic Calcium Carbonate (Aragonite/Conchiolin)

Turquoise and Red Coral (with Grizzly Bear Claw)

Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Precious Coral (Corallium rubrum)

Turquoise

Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]

Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Black Onyx

Silicon dioxide (SiO2) - Chalcedony variety

Epidote with Quartz and Feldspar

Ca2(Al2,Fe3+)(SiO4)3(OH) (Epidote complex)

Orange Calcite

Calcium Carbonate (CaCO3)

Orange Calcite

Calcium Carbonate (CaCO3)

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

Fancy Jasper (Multicolor Agate/Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Sandstone (Ferruginous)

Arenite with Iron Oxide staining (Fe2O3)

Petrified Wood

Silicified Wood (SiO2)

Amazonite

K(AlSi3O8), Microcline (potassium feldspar)

Chert (Arrowhead Debitage or Spall)

Silicon Dioxide (SiO₂)

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Chalcedony (Agatized Coral / Rough Chalcedony Node)

Silicon Dioxide (SiO2)

Jasper

Silicon dioxide (SiO2)

White Marble

Calcite-rich Metasomatized Carbonate (CaCO3)

Rough Corundum (likely Sapphire/Zircon-bearing)

Aluminium Oxide (Al2O3)

Green Calcite

Calcite (CaCO3)

Jasper (Iron-stained Chert)

Silicon Dioxide (SiO2)

Quartz (on matrix)

Quartz (Silicon Dioxide, SiO₂)

Turquoise

Turquoise (CuAl6(PO4)4(OH)8·4H2O)

Ethiopian Fire Opal

Hydrated Silica (SiO2·nH2O)

Orthoclase Feldspar

KAlSi3O8 (Potassium Aluminum Silicate)