Apache Tear
Obsidian (Hydrated Volcanic Glass, SiO2)
igneous
Category
Igneous Rock (Volcanic Glass)
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
Basalt
Basalt (principally composed of pyroxene and plagioclase feldspar)
igneous
Obsidian
Volcanic glass (SiO2-rich amorphous silicate)
igneous
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
mineral
Chalcedony (specifically Agate or Moonstone-like Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz Druze on Matrix
Silicon Dioxide (SiO2)
mineral
Quartz Druzy on Agate (River Cobble)
Silicon Dioxide (SiO2)
Mineral / Sedimentary (often associated with volcanic hosts)
Basalt
Basalt (containing mainly Plagioclase feldspar and Pyroxene)
igneous
Agate Slices and Clear Quartz Points
Agate (SiO2 Chalcedony) and Clear Quartz (SiO2 Crystalline)
mineral
Diorite (Salt and Pepper Rock)
Diorite
igneous
Chalcedony (variations like Agate or Jasper)
Chalcedony (SiO₂ - microcrystalline quartz)
Mineral
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Pink Granite
Felsic intrusive igneous rock (composition: SiO2 and Al2O3)
igneous
Sunkissed Quartz or Hematoid Quartz
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
mineral
Prehnite
Prehnite Ca2Al2Si3O10(OH)2
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
White Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
igneous
Quartz (Iron-Stained or Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Granite Cobble
Phaneritic Felsic Igneous Rock (Granite)
igneous
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
igneous
Milky Quartz (Water-worn Pebble)
Silicon Dioxide (SiO2)
mineral
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous
Tektite (specifically Indochinite)
Tektite (Natural silica glass)
Mineraloid (Impact glass)
Apache Tear (Obsidian)
Obsidian (Hydrated Amorphous Silica, SiO2 + MgO/Fe3O4)
igneous
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
sedimentary
Grey Chalcedony (Agate)
Silicon Dioxide (SiO2)
mineral
Quartz (specifically Milky or Clear Quartz fragment)
Silicon Dioxide (SiO2)
mineral
Quartz (Milky or Smoky variety)
Silicon Dioxide (SiO2)
mineral
Diorite (Salt and Pepper Rock)
Phaneritic plutonic igneous rock (sodium-rich plagioclase feldspar and hornblende)
igneous
Greenschist / Greenstone
Greenschist facies metabasite
metamorphic
Vesicular Basalt (Amygdaloidal)
Vesicular Basalt (Fe-Mg rich extrusive volcanic rock)
igneous
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Mineral
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions (SiO2 + Fe2O3)
Igneous
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
mineral
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Clear Quartz
Silicon Dioxide (SiO2)
mineral
Chalcedony (Smoky Quartz or Agate nodule fragment)
Silicon Dioxide (SiO2)
mineral
Basalt
Mafic Volcanic Basalt (Major minerals: Plagioclase feldspar, Pyroxene; Minor: Olivine, Magnetite)
igneous
Basalt
Basalt
Igneous
Scoria (Vesicular Basalt)
Vesicular Basalt
igneous