Milky Quartz
Silicon Dioxide (SiO2)
Category
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
Milky Quartz
Silicon Dioxide (SiO2)
Basalt with vesicles (Amygdaloidal Basalt)
Amygdaloidal Basalt (predominantly Plagioclase and Pyroxene)
Banded Chert (Agate)
Silicon Dioxide (SiO2)
Jasper with Quartz inclusions
Silicon Dioxide (SiO2)
Amygdaloidal Basalt
Vesicular-Amygdaloidal Basalt (Mafic Extrusive)
Basalt with Caliche Crust
Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Basalt
Mafic volcanic rock (Silicon dioxide 45-52%)
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Blue Sapphire
Corundum (Al2O3)
Basalt with Quartz/Feldspar Inclusion
Basalt (containing Silicate minerals such as SiO2 and (Ca,Na)(Al,Si)4O8)
Green Quartz (Prasiolite)
Silicon Dioxide (SiO2) with trace impurities
Carnelian Agate
Carnelian (SiO2 with iron oxide impurities)
Rough Sapphire (Corundum)
Corundum (Al2O3)
Blue Chalcedony
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Basalt
Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)
Clear Quartz
Silicon Dioxide (SiO2) / Rock Crystal
Granite Pebble
Granite (Phaneritic Acidic Igneous Rock)
Greenstone
Greenschist / Greenstone (containing Chlorite, Epidote, Actinolite)
Obsidian
Obsidian (Volcanic Glass) SiO2 (70% or more)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Diorite (Salt and Pepper Rock)
Diorite
Quartz Vein / Milky Quartz
Silicon Dioxide (SiO2)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Hematite/Magnetite inclusions)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt (River Pebble)
Basalt
Basalt Pebble with Epidote/Olivine
Vitreous Basalt (SiO2 with Ca/Mg/Fe silicates)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Basalt with Vesicular Texture
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Scoria (Lava Rock)
Scoria (highly vesicular extrusive igneous rock)
Snowflake Obsidian
Spherulitic Obsidian (primarily SiO2)
Tektite (Indochinite)
Tektite (SiO2 + Al2O3, Glassy Melts)
Vesicular Basalt (Scoria)
Mafic extrusive igneous rock (primarily Plagioclase Feldspar and Pyroxene)
Obsidian
Obsidian (principally SiO2 + MgO, Fe3O4)
Basalt (Water-worn pebble)
Basalt (Mafic Extrusive Rock)
Agate
Silicon Dioxide (SiO2) - Chalcedony variant
White Agate (Chalcedony)
Silicon Dioxide (SiO2)
Obsidian
Volcanic Glass (70-75% SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity)
Tumbled Obsidian (possibly Mahogany Obsidian variant)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)