Obsidian
Volcanic Glass (SiO2)
Category
Browse mineral (synthetic glass) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2)
Quartz (Citrine or Iron-Stained)
Silicon Dioxide (SiO2)
Quartz
Silicon dioxide (SiO2)
Sandstone
Sedimentary Rock (Quartz arenite or arkose)
Sandstone
Arenite (primarily SiO2)
Rounded quartz-rich pebble
Likely milky quartz or quartzite (SiO₂)
Quartz (with probable host rock)
Silicon Dioxide (SiO2)
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
Quartz Pebble
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite
Obsidian
Amorphous volcanic glass (70-75% SiO2)
Weathered gray granitic rock
Granite, likely quartz–feldspar–mica aggregate
Quartz in Matrix (or Quartz Vein Rock)
Silicon Dioxide (SiO2) with host rock
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz Pebble (with Iron Staining)
Crystalline Silicon Dioxide (SiO2)
Weathered, iron-stained quartz-rich pebble (uncertain identification)
Microcrystalline quartz, SiO₂, with iron-oxide/hydroxide staining and dark matrix inclusions
Sandstone
Sedimentary Rock (Quartzose Sandstone)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Quartz
Silicon Dioxide (SiO2)
Smoky Quartz in Matrix
Silicon Dioxide (SiO2)
Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartz Sand Gravel
Silicon Dioxide (SiO2)
Quartz Pebble (often referred to as 'Sea Glass' or 'River Stone' when worn smooth)
Silicon Dioxide (SiO2)
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Sandstone
Clastic sedimentary rock (Quartz arenite)
Sandstone
Sedimentary Clastic Rock
Sandstone
Arenite (SiO2 principal)
Mahogany Obsidian
Volcanic Glass (with inclusions of Magnetite or Hematite)
Obsidian
Volcanic glass (primary composition: SiO2)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Orthoclase Feldspar
KAlSi3O8 (Potassium aluminum silicate)
Chert (Flint)
Microcrystalline quartz (SiO2)
Sandstone with Iron Staining
Clastic sedimentary rock (SiO2 with iron oxides)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Quartz-rich rock, likely milky quartz or quartzite
Quartz (SiO₂); possibly quartzite, a recrystallized quartz sandstone
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Quartz Vein Rock
Silicon Dioxide (SiO2)
White Quartz
Silicon Dioxide (SiO2)