Igneous And Mineral

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Rainbow Obsidian

Volcanic glass (SiO2 - approximately 70% or more silicon dioxide)

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Mahogany Obsidian

Obsidian (volcanic glass with hematite/magnetite inclusions)

Green Aventurine and Clear Quartz

Green Aventurine (Silicon Dioxide - SiO2 with Fuchsite inclusions); Clear Quartz (Silicon Dioxide - SiO2)

Basalt with Limonite stains

Extrusive mafic igneous rock; Limonite (FeO(OH)·nH2O)

Black Obsidian

Volcanic Glass (predominantly SiO2)

Diorite

Phaneritic Intrusive Igneous Rock (Intermediate Composition)

Common Opal in Host Rock

Hydrated Silica (SiO2·nH2O)

Iron-Stained Quartz (Riverside Cobble)

Silicon Dioxide (SiO2) with Limonite/Hematite inclusions

Granite

Intrusive Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Granite (Weathered/Oxidized)

Phaneritic Felsic Igneous Rock (composed of Quartz, Orthoclase Feldspar, and Mica)

Rough Amethyst

Silicon Dioxide (SiO2) with Iron impurities

Porphyritic Basalt (with Quartz or Calcite inclusion)

Porphyritic Basalt (Matrix: SiO2/MgO/FeO, Phenocryst: likely Quartz or Calcite)

Granite (Pink/Potassium Feldspar Granite)

Felsic Plutonic Rock (Potassium Feldspar, Quartz, Mica, and Amphibole)

Rough Star Sapphire (Corundum)

Al2O3 (Aluminum Oxide)

Granite

Phaneritic Plutonic Igneous Rock (composed of quartz, alkali feldspar, and plagioclase)

Quartz Crystal (specifically a small Clear Quartz point)

Silicon Dioxide (SiO2)

Labradorite

Labradorite ((Ca, Na)(Al, Si)4O8)

Pearl (with Peridot)

Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4

Massive Milky Quartz (with Iron Inclusions)

Quartz (Silicon Dioxide, SiO2)

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Smoky Quartz

Silicon Dioxide (SiO2)

Pink Granite

Phaneritic Plutonic Felsic Rock (Granite)

Diorite (Salt and Pepper Rock)

Diorite

Diorite (Salt and Pepper Rock)

Phaneritic plutonic igneous rock (sodium-rich plagioclase feldspar and hornblende)

Druzy Quartz on Host Rock

Silicon Dioxide (SiO2) with various iron-oxide inclusions

Amazonite

Amazonite (KAlSi3O8, a triclinic variety of Potassium Feldspar)

Quartz (specifically Milky Quartz/Quartzite)

Silicon Dioxide (SiO2)

Granodiorite

Granodiorite (containing quartz, plagioclase, and biotite/hornblende)

Diorite

Diorite

Chevron Amethyst

Silicon Dioxide (SiO2) with iron impurities

Olivine Basalt

Mafic Volcanic Rock (rich in (Mg, Fe)2SiO4)

Vesicular Basalt (Scoria)

Vesicular Basalt

Granite

Granitic intrusive igneous rock

Smoky Quartz and Clear Quartz Geode

Silicon Dioxide (SiO2)

Basalt

Basalt (dominated by plagioclase feldspar and pyroxene minerals)

Lapis Lazuli

Na8(Al6Si6O24)S2 (composed primarily of Lazurite, Calcite, and Pyrite)

Quartz (Milky/Clear)

Silicon Dioxide (SiO2)