Sedimentary And Igneous (Mixed)

Obsidian

Obsidian (Volcanic Glass)

Granite (Thin Section)

Granite (Felsic Plutonic Rock)

Quartz with Mica inclusion

Silicon Dioxide (SiO2) with Muscovite/Biotite inclusions

Feldspar Rich Granite with Limonite Staining

K-Feldspar Granite (KAlSi3O8)

Scoria (Lava Rock)

Mafic Volcanic Scoria

Obsidian

Volcanic Glass (SiO2 rich)

Obsidian

Volcanic glass (SiO2 + impurities)

Amygdaloidal Basalt

Amygdaloidal Basalt (Host rock) with Quartz or Calcite amygdules

Mahogany Obsidian

Obsidian (volcanic glass with Hematite/Magnetite inclusions)

Pumice

Extrusive volcanic rock (Vesicular Rhyolite/Dacite/Andesite)

Porphyritic Basalt (Leopard Rock)

Porphyritic Mafic Volcanic Rock

Obsidian

Obsidian (Volcanic glass), SiO2 (major component)

Granite

Phaneritic Felsic Igneous Rock (Granite)

Porphyritic Basalt (River Rock)

Porphyritic Basalt

Granite Cobble

Felsic Intrusive Igneous Rock

Porphyritic Basalt

Basalt with plagioclase phenocrysts

Obsidian

Volcanic glass (primary composition: SiO2)

Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)

Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)

Pink Granite (Alkali Feldspar Granite)

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8)

Tan Brown Granite

Phaneritic Biotite-Feldspar Granite

Basalt with Quartz/Calcite Vein

Amygdaloidal Basalt (matrix) with Mineral Vein filling

Obsidian

Volcanic Glass (predominantly SiO2)

Obsidian

Volcanic glass (high silica content based on SiO2)

Sodalite-rich Syenite (Yooperlite)

Sodalite-rich Syenite (Na8(Al6Si6O24)Cl2 within an igneous matrix)

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Limonitic Scoria (Vesicular Basalt with Iron Staining)

Highly vesicular basalt heavily stained by Limonite [FeO(OH)·nH2O]

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions

Granite

Phaneritic Plutonic Rock (Granite)

Obsidian (worked into an arrowhead profile)

Obsidian (volcanic glass), primarily SiO2 (Silicon Dioxide)

Porphyry (specifically Porphyritic Rhyolite or Andesite)

Porphyritic Igneous Rock (composed of Phenocrysts in an Aphanitic groundmass)

Pink Granite

Phaneritic intrusive igneous rock (Felsic)

Granitic Pegmatite

Granitic Pegmatite (principally Quartz, Potassium Feldspar, and Mica)

Granodiorite

Granodiorite (intermediate plutonic rock)

Amygdaloidal Basalt

Amygdaloidal Basalt containing Zeolite and Calcite inclusions

Granite Cobble

Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)

Amygdaloidal Basalt

Amygdaloidal Basalt (Mafic Extrusive)

Granite

Phaneritic Felsic Igneous Rock

Obsidian

Volcanic glass (no mineral formula due to amorphous structure, mostly SiO2)

Granite

Granite (Phaneritic intrusive igneous rock)

Diabase (Greenstone)

Diabase (also known as Dolerite)

Stardust (Micrometeorite)

Chondrite / Micrometeorite (Extraterrestrial Silicate)

Porphyritic Rhyolite

Porphyritic Rhyolite