Obsidian
Volcanic glass
Category
Browse synthetic glass specimens identified by the Rock Identifier community.
Obsidian
Volcanic glass
Obsidian
Volcanic glass
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Muscovite Mica
KAl2(AlSi3O10)(F,OH)2
Muscovite Mica (with Quartz matrix)
Muscovite - KAl2(AlSi3O10)(OH)2
Blue Goldstone
Aventurine Glass (Silicon Dioxide with metal inclusions)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Obsidian (Volcanic Glass)
Sea Glass (Turquoise/Aqua)
Amorphous Silica (SiO2) with transition metal dopants
Blue Goldstone
Goldstone (artificial glass)
Aventurine Quartz
Silicon Dioxide (SiO2) with Fuchsite inclusions
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Drusy/Crystalline)
Silicon Dioxide (SiO2)
Obsidian
Volcanic glass
Quartz
Silicon Dioxide (SiO2)
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
Obsidian
Obsidian (volcanic glass; primarily SiO2)
Muscovite Mica (Granitic Pegmatite)
Muscovite - KAl2(AlSi3O10)(OH)2
Banded Chert (Flint)
Microcrystalline Quartz (SiO2)
Quartz (Milky to Clear)
Silicon Dioxide (SiO2)
Pumice
Pumice (a highly vesicular, silicic volcanic rock)
Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Lemon Quartz (Orizaba/Citrinated Quartz)
Silicon Dioxide (SiO2) with iron impurities/treatment
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Obsidian
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Mica (Biotite or Phlogopite variety)
Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Quartz / Common Opal
Silicon Dioxide (SiO2)
Quartz / Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Grain/Fragment)
Silicon Dioxide (SiO2)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Green Aventurine
Quartzite with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)
Quartz with Mica inclusions (likely Iron-stained)
Silicon Dioxide (SiO2) with Phyllosilicates
Slag Glass
Amorphous Silica / Glass Slag
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
Slag (Industrial Glass Slag)
Amorphous Silica / Ferro-silicate Slag
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)