Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Category
Browse sedimentary rock (possibly a conglomerate or coarse grained sandstone) specimens identified by the Rock Identifier community.
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Basalt
Extrusive mafic igneous rock
Basalt
Basalt
Basalt
Mafic volcanic rock (Primarily Plagioclase Feldspar and Pyroxene)
Basalt
Mafic Igneous Rock
Quartzite with Quartz Veins
Quartzite (chiefly SiO2)
Chert (Gravel specimen)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Jasper (Skull Carving)
Jasper (Silicon Dioxide, SiO2 plus Iron Oxide inclusions)
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
Basalt Pebble
Basalt (Mafic volcanic rock)
Petrified Wood (Calamites Fossil)
Calamites sp. (Silicified/Permineralized Plant Fossil)
Basalt
Basalt
Quartzite with Quartz Vein
Metamorphosed sandstone (SiO2)
Basalt
Basalt (Mafic volcanic rock)
Basalt with Plagioclase Microphenocrysts
Amygdaloidal or Porphyritic Basalt
Basalt (River Pebble)
Basalt
Basalt
Basalt (containing Pyroxene, Plagioclase feldspar, and Olivine)
Quartzite pebble
Metamorphic rock (mainly SiO2)
River Pebble (Likely Quartzite or Chert)
Quartzite (primarily SiO2)
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Basalt
Basalt (Mafic Extrusive)
Basalt (Road Aggregate / Crushed Stone)
Aphanitic Mafic Igneous Rock
Basalt (Weathered/Tumbled)
Extrusive Mafic Igneous Rock
Quartzite Pebble
Metamorphic Quartz (SiO2)
Quartzite
Quartzite (90%+ SiO2)
Basalt
Extrusive mafic igneous rock
Basalt
Basalt (Vitreous to Aphanitic Mafic Igneous Rock)
Granite
Phaneritic plutonic rock (dominated by SiO2, Al2O3, K2O, Na2O)
Basalt (Stream-worn Cobble)
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Basalt
Extrusive Mafic Igneous Rock
River Quartzite Pebble
Quartzite (SiO2)
Basalt
Basalt
Basalt
Basalt (Mafic volcanic rock)
Jasper (specifically Owyhee or Picture Jasper variety)
Jasper (Silicon Dioxide, SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Basalt with Vesicular Texture
Basalt (SiO2 range 45-52%)
Basalt
Extrusive mafic igneous rock
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (SiO2)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Basalt (River Pebble)
Extrusive Mafic Igneous Rock