Volcanic Glass (Igneous)

Snowflake Obsidian

Volcanic glass with Cristobalite inclusions (70–75% SiO2)

Gold Sheen Obsidian

Obsidian (volcanic glass with SiO2 + gas inclusions)

Black Sapphire (Basaltic Blue Sapphire)

Corundum (Al2O3)

Orbicular rhyolite (orbicular jasper-like volcanic rock)

Orbicular rhyolite; predominantly quartz, alkali feldspar, plagioclase, and volcanic glass, with concentric spherulitic growths

Obsidian

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

Pumice (likely)

Pumice, vesicular volcanic glass; typically silica-rich rhyolitic to dacitic composition

Tumbled black obsidian (likely)

Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, amorphous)

Snowflake Obsidian

Obsidian with Cristobalite inclusions (SiO2)

Scoria (Lava Rock)

Vesicular Basalt / Scoria

Polished black obsidian

Volcanic glass; predominantly rhyolitic glass, approximately 70–80% SiO₂

Snowflake Obsidian

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

Black Obsidian

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

Pumice

Pumicite

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Obsidian flake

Volcanic glass; primarily silica-rich rhyolitic composition (approximately SiO₂)

Blue Obsidian

Obsidian

Weathered vesicular volcanic rock (likely scoria or vesicular basalt)

Vesicular basalt/scoria; primarily plagioclase, pyroxene, olivine, and volcanic glass

Rhyolite

Rhyolite (High-silica volcanic rock)

Pumice

Vesicular Rhyolite or Trachyte (High-silica volcanic glass)

Black tourmaline (schorl), possibly rough obsidian

Schorl tourmaline: NaFe₃Al₆(BO₃)₃Si₆O₁₈(OH)₄; visual confirmation is limited

Black volcanic glass (likely obsidian)

Obsidian; predominantly rhyolitic volcanic glass composed chiefly of amorphous SiO₂

Rhyolitic Tuff (Breccia Type)

Rhyolitic Pyroclastic Rock (Mixed Silicates including Quartz, Feldspar, and Volcanic Glass)

Basalt with Plagioclase or Quartz Inclusion

Melanocratic Basalt with Porphyritic Inclusion

Quartz-bearing volcanic rock, likely vesicular basalt

Basalt with secondary quartz (SiO₂) and possible zeolite/chalcedony infill

Pumice

Pumice, a highly vesicular volcanic rock composed mainly of rhyolitic or dacitic glass

Likely pumice or vesicular volcanic rock

Pumice; predominantly volcanic glass (silica-rich, commonly rhyolitic or dacitic)

Polished dark stone, possibly obsidian

Volcanic glass; likely rhyolitic obsidian (SiO₂-rich, noncrystalline)

Vesicular basalt

Basalt, commonly composed of plagioclase, pyroxene, olivine, and volcanic glass

Porous volcanic rock (likely pumice)

Pumice; vesicular volcanic glass, typically silica-rich

Pumice (likely basaltic pumice/scoria)

Vesicular volcanic rock, commonly basaltic; mainly plagioclase, pyroxene, and volcanic glass

Vesicular volcanic tuff (likely scoriaceous tuff)

Lithified pyroclastic rock composed chiefly of volcanic ash, glass, and lithic fragments

Pumice

Pumice (a highly vesicular extrusive igneous rock)

Black Obsidian

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

Obsidian (likely snowflake or volcanic-glass variety)

Volcanic glass, predominantly rhyolitic in composition; mainly SiO₂ with minor Al, Na, K, Fe, and Ca

Obsidian

Volcanic glass (SiO2-rich amorphous silicate)

Tumbled amethyst

Amethyst, purple variety of quartz (SiO₂)

Polished mahogany obsidian (likely)

Volcanic glass; primarily silica-rich rhyolitic glass (SiO₂), with iron oxides

White Agate / Chalcedony

Silicon Dioxide (SiO2)

Pumice or vesicular volcanic rock

Pumice; chiefly volcanic glass (silica-rich, composition commonly rhyolitic to dacitic)

Obsidian

Volcanic glass (SiO2 - Silicon Dioxide with impurities)

Pumice

Vesicular volcanic glass, composition commonly rhyolitic to dacitic (SiO₂-rich)

Mixed tumbled stones, likely rose quartz and purple quartz/amethyst

Quartz (SiO₂), including amethyst and probable rose quartz; exact identification is uncertain from the blurred image