Quartz in Matrix (possibly with Biotite or Hornblende)
Quartz (Silicon Dioxide, SiO2) in Granitic Matrix
Category
Browse igneous specimens identified by the Rock Identifier community.
Quartz in Matrix (possibly with Biotite or Hornblende)
Quartz (Silicon Dioxide, SiO2) in Granitic Matrix
Pumice (specifically a water-worn, weathered variety)
Vesicular volcanic glass
Diorite
Diorite
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Basalt
Basalt (composition of Plagioclase feldspar, Pyroxene, and Olivine)
Obsidian
Obsidian (principally SiO2)
Granite
Granite (composed of Quartz, Alkali Feldspar, and Plagioclase)
Basalt River Stone
Basalt
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Pumice
Pumiceous rhyolite / Volcanic glass
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Basalt
Basalt (containing mainly Plagioclase feldspar and Pyroxene)
Wonderstone (Banded Rhyolite)
Rhyolite (Silicon Dioxide with Iron Oxide impurities)
Basalt
Basalt
Obsidian
Obsidian (Volcanic Glass)
Scoria (Lava Rock)
Scoriaceous Basalt
Basalt with Epidote Veining
Basalt (Mafic Extrusive Rock) with Ca2(Al,Fe)3(SiO4)3(OH)
Granite
Granite (Mainly Quartz, Feldspar, and Mica/Amphibole)
Amygdaloidal Basalt
Amygdaloidal Basalt (with secondary mineral infilling)
Basalt (River Rock Cobble)
Extrusive mafic volcanic rock (Basalt)
Obsidian
Volcanic glass (Mainly SiO2)
Basalt with Porphyritic Texture
Porphyritic Basalt
Scoria
Vesicular Basaltic Glass
Granite
Granite (composed primarily of Quartz SiO2, Feldspar KAlSi3O8, and Mica K(Mg,Fe)3AlSi3O10(OH)2)
Porphyritic Basalt
Porphyritic Basalt (with Plagioclase phenocrysts)
Scoria (Lava Rock)
Mafic Vesicular Volcanic Rock
Obsidian with Mahogany Phasing
Volcanic Glass (SiO2 + Fe2O3)
Granite
Felsic Plutonic Rock (Granite)
Lava Stone and Chakra Beads
Basalt (with various mineral/synthetic beads)
Coarse-grained Granite (Quartz and Feldspar dominated)
Granitoid (KAlSi3O8 – NaAlSi3O3 – CaAl2Si2O8 – SiO2)
Granite
Granite (Felsic Plutonic Rock)
Granite
Granite
Peridotite
Ultramafic intrusive rock (Peridotite)
Granite Pebble
Granite (Phaneritic Quartz-Feldspar Rock)
Obsidian
Amorphous volcanic glass (SiO2)
Vesicular Basalt
Basalt with secondary mineral infilling (Amygdaloidal Basalt)
Granite
Granite (Mainly Quartz SiO2, Alkali Feldspar (K,Na)AlSi3O8, and Plagioclase Feldspar)
Iron-Nickel Meteorite (Possible Chondrite or Oxidized Iron)
Siderite (Nickel-Iron) or Chondrite (Si/Fe composite)
Basalt
Basalt
Labradorite (Larvikite variety)
Plagioclase Feldspar (Na,Ca)(Si,Al)4O8
Vesicular Basalt
Vesicular Basalt (rich in silicate minerals mostly Plagioclase and Pyroxene)
Iron-Nickel Meteorite
Siderite (Iron Meteorite), primarily Fe-Ni alloy