Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Hematite/Magnetite inclusions)
Category
Browse synthetic glass (man made) specimens identified by the Rock Identifier community.
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Hematite/Magnetite inclusions)
Quartzite River Rock
Quartzite (primarily SiO2)
Obsidian / Volcanic Glass
Obsidian (principally SiO2, usually 70% or more)
Quartzite (River Cobble)
Quartzite (predominantly SiO2)
Chert (Agate/Flint variant)
Microcrystalline Quartz (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz (Druzy)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
Obsidian
Obsidian (volcanic glass), amorphous SiO2 + impurities
Obsidian
Obsidian (Amorphous Volcanic Glass, SiO2)
Jasper (Multi-colored) / Sea Glass Slag
Silicon Dioxide (SiO2) with impurities of Iron Oxide
Pumice
Pumice (Vitreous pyroclastic rock)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz with Chlorite/Mica inclusions
Silicon Dioxide (SiO2) with phyllosilicate inclusions
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Chert (and Flint)
Chert (SiO2)
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Sandstone (Quartzite Pebble)
Arenite / Metamorphosed Sandstone (SiO2)
Citrine
Silicon Dioxide (SiO2) with iron impurities
Citrine Quartz Sphere
Silicon Dioxide (SiO2)
Quartzite
Quartzite (SiO2)
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Quartzite Pebble
Metamorphic Quartz (SiO2)
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
Rose Quartz
SiO2 (Silicon Dioxide)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Libyan Desert Glass
Tektite (high-silica impact glass), SiO2 + tracing minerals
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Chert / Flint
Microcrystalline or cryptocrystalline quartz (SiO2)