Sedimentary And Igneous (Mixed)

Granite (Weathered)

Granite (Felsic Plutonic Rock)

Granite

Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica)

Pink Granite

Felsic Intrusive Igneous Rock (composed primarily of K-Feldspar, Quartz, and Mica)

Obsidian

Volcanic Glass (Amorphous Silica)

Diorite

Diorite (Intermediate intrusive igneous rock)

Basalt

Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)

Vesicular Basalt with Epidote

Vesicular Basalt (Mg, Fe)2SiO4 with Epidote (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH))

Black Obsidian

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

Diabase (Dolerite) Cobble

Diabase / Dolerite

Granite

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

Basalt

Mafic Volcanic Rock (composed of Plagioclase Feldspar and Pyroxene)

Diorite

Intermediate plutonic igneous rock

Scoria (Lava Rock)

Mafic extrusive volcanic rock (Scientific formula varies based on mineral content: primarily SiO2, MgO, and FeO)

Basaltic Scoria

Scoria (Vesicular Basalt/Andesite)

Gabbro

Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)

Diorite

Phaneritic intermediate plutonic rock

Vesicular Basalt (Iron-Stained)

Mafic Volcanic Rock (Basalt)

Obsidian

Amorphous volcanic glass (70-75% SiO2)

Schorl (Black Tourmaline) in Quartz or Feldspar Matrix

NaFe3Al6(BO3)3Si6O18(OH)4 (Schorl) in Granitic Pegmatite

Gold Sheen Obsidian

Volcanic Glass (SiO2 + Fe3O4 / Gas Inclusions)

Obsidian

Obsidian (Volcanic Glass, primarily SiO2)

Obsidian

Volcanic Glass (70% or more SiO2)

Granite (with Muscovite Mica)

Phaneritic Felsic Igneous Rock (primarily Quartz SiO2, K-Feldspar KAlSi3O8, and Muscovite KAl2(AlSi3O10)(OH)2)

Basalt

Basalt (Mafic volcanic rock)

Pink Granite

Phaneritic Felsic Igneous Rock (Granite, rich in Potassium Feldspar)

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Peridotite (Dunite)

Peridotite (mostly Olivine: (Mg,Fe)2SiO4)

Obsidian

Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)

Obsidian

Obsidian (Amorphous volcanic glass, SiO2 rich)

Basalt

Mafic Igneous Rock (composed primarily of Plagioclase and Pyroxene)

Black Obsidian

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

Granodiorite

Granodiorite (calc-alkaline phaneritic igneous rock)

Amygdaloidal Basalt

Amygdaloidal Basalt with Secondary Infilling (e.g., Agate, Quartz, or Zeolite)

Obsidian

Volcanic Glass (70-75% SiO2)

Glacial Cobble (likely Granitic or Gneissic)

Granite/Gneiss Glacial Erratic

Granite Pegmatite with Tourmaline and Muscovite

Pegmatite (Feldspar: KAlSi3O8, Quartz: SiO2, Schorl: NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH))

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Porphyritic Andesite

Andesite (porphyritic variety)

Labradorite (Larvikite variety)

Ternary feldspar (Anorthoclase), (Na,K)AlSi3O8

Pumice

Pumice (Vesicular Felsic Glass)

Limonite-stained Granite

Felsic Plutonic Rock with Hydrated Iron Oxides

Granite Pebble

Granite (Phaneritic Acidic Igneous Rock)