Sedimentary Or Igneous (Host Environment)

Turquoise (Green variety)

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

Basalt (River Pebble)

Mafic volcanic rock (rich in magnesium and iron)

Pyrite

Iron Sulfide (FeS2)

Chalcedony Pebble

Cryptocrystalline Quartz (SiO2)

Chalcedony (Agate Pebble)

Silicon Dioxide (SiO2)

Ferruginous Sandstone

Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)

Ferruginous Sandstone

Clastic Sedimentary Rock (Iron-rich)

Quartz Geode with Chalcedony

Crystalline Silicon Dioxide (SiO2)

Chert (Arrowhead Debitage or Flake)

Microcrystalline silica (SiO2)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Yellow Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz (Water-Worn Pebble)

Silicon Dioxide (SiO2)

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Glauconitic Sandstone

Greensand (Glauconite-bearing sandstone)

Botryoidal Quartz

Silicon Dioxide (SiO2)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Magnetite / Iron Ore

Magnetite (Fe3O4)

Blue Lace Agate

Agate (Variety of Chalcedony, SiO2)

Turquoise

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

Basalt River Stone

Basalt

Copper Ore (with Malachite and Azurite)

Hydroxide copper carbonate (Cu2CO3(OH)2 / Cu3(CO3)2(OH)2)

Sandstone (Water-worn Pebble)

Clastic sedimentary rock (primarily SiO2)

Jadeite

Jadeite (NaAlSi2O6)

Azurite and Malachite on Matrix

Azurite: Cu3(CO3)2(OH)2; Malachite: Cu2CO3(OH)2

Granite Pebble

Phaneritic Felsic Igneous Rock

Basalt River Pebble

Basalt (Aphanitic Mafic Igneous Rock)

Granite River Pebble

Phaneritic Felsic Igneous Rock (Granite)

Stream Pebble (Basalt/Greywacke)

Mafic Igneous Rock (Fine-grained)

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Glauconitic Sandstone

Glauconitic Sandstone (complex silicate formula: (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2)

Fossiliferous Shale Matrix

Clastic Sedimentary Rock with Brachiopod or Mollusk shell fragments

Granite Cobble

Phaneritic Felsic Igneous Rock

Amethyst

SiO2 (Silicon Dioxide with iron impurities)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Basalt River Cobble

Basalt (Mafic Igneous Rock)

Barite Rose on Marcasite

Barium Sulfate (BaSO4) on Iron Sulfide (FeS2)

Chalcedony (Quartz Nodule)

Silicon Dioxide (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Basalt River Stone

Basalt

Druzy Quartz

Crystalline Silicon Dioxide (SiO2)

Apache Tear (Obsidian)

Volcanic glass (SiO2 - Silicon Dioxide)