Igneous Rock (Volcanic Glass)

Obsidian

Obsidian (Volcanic Glass, ~70–75% SiO2)

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Basalt with Iron Oxidation

Aphanitic Mafic Igneous Rock (composed primarily of Plagioclase and Pyroxene)

Pink Granite

Phaneritic Felsic Intrusive Igneous Rock

Pink Granite

Phaneritic intrusive felsic igneous rock

Quartz Geode (Cracked Open)

Quartz (Silicon Dioxide - SiO2)

Snowflake Obsidian

Hydrated Volcanic Glass (primarily SiO2) with Cristobalite inclusions

Jasper (specifically Bloodstone/Heliotrope or Dark Green Jasper)

Cryptocrystalline Quartz (SiO2) with inclusions

Basalt

Basalt (Mafic Extrusive Igneous Rock)

Quartz River Pebble

Quartz (Silicon Dioxide, SiO2)

Obsidian

Amorphous volcanic glass (primarily SiO2)

Quartz Geode

Silicon Dioxide (SiO2)

Pink Granite

Phaneritic intrusive igneous rock (K-feldspar rich)

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Granodiorite (Riverbed Cobble)

Granodiorite

Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Basalt

Basalt (Mafic Extrusive)

Quartz (Milky/Common Quartz)

Silicon Dioxide (SiO2)

Lava Rock (Scoria)

Extrusive basaltic scoria

Basalt

Basalt (Composition primarily Plagioclase feldspar, Pyroxene, and Olivine)

Porphyry

Porphyritic Igneous Rock (likely Porphyritic Andesite or Basalt)

Mahogany Obsidian

Obsidian (Volcanic Glass with Hematite/Magnetite inclusions), SiO2

Obsidian

Obsidian (Volcanic Glass, SiO2 + impurities)

Vesicular Basalt

Vesicular Basalt (Aphanitic Mafic Rock)

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Yellow Quartz (Citrine/Yellow Jasper mix)

Silicon Dioxide (SiO2)

Que Sera Stone (Llanite)

Rhyolite containing blue quartz and feldspar

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Thunderegg (specifically a Jasper/Agate-filled Geode nodule)

Silicon Dioxide (SiO2) within Rhyolitic Matrix

Black Obsidian

Volcanic Glass (70–75% SiO2 plus MgO, Fe3O4)

Snowflake Obsidian

Volcanic Glass with Spherulite Inclusions (70-75% SiO2)

Jasper

Silicon Dioxide (SiO2) with impurities

Red Jasper

Jasper (Silicon Dioxide, SiO2 with Fe2O3 inclusions)

Mahogany Obsidian

Volcanic Glass with Hematite/Magnetite inclusions

Granite (specifically the Ubatuba variety)

Phaneritic Igneous Rock (Granodiorite/Monzogranite)

Clear Quartz

Quartz (Silicon Dioxide, SiO2)

Mahogany Obsidian

Volcanic glass containing Magnetite/Hematite

Rose Quartz

Silicon Dioxide with trace inclusions of dumortierite or titanium (SiO2)

Pegmatite

Coarse-grained Igneous Rock (Granitic Pegmatite)

Basalt (Weathered Pebble)

Extrusive mafic rock (primarily Plagioclase Feldspar and Pyroxene)

Carnelian (a variety of Chalcedony)

SiO2 (Silicon Dioxide with Iron Oxide impurities)

Basalt

Mafic Volcanic Rock (primarily Plagioclase and Pyroxene)