Basalt (Beach Pebble)
Extrusive mafic igneous rock
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Basalt (Beach Pebble)
Extrusive mafic igneous rock
Basalt River Stone
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Basalt (Water-worn Pebble)
Mafic Volcanic Rock (High in Fe and Mg)
Basalt
Extrusive mafic igneous rock
Basalt
Basalt (composition of plagioclase feldspar, pyroxene, and olivine)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Basalt
Basalt
Quartzite
Quartzite (SiO2)
Basalt
Basalt (Volcanic Mafic Rock)
Granular Sandstone
Arenite (variable composition, primarily SiO2)
Eclogite
Eclogite (Omphacite + Pyrope)
Sandstone (Ferruginous)
Arenite (complex silicate composition with iron oxides)
Basalt River Stone
Aphanitic Mafic Igneous Rock
Basalt
Basalt (Mafic igneous rock)
Basalt
Extrusive mafic igneous rock
Porphyritic Basalt with Quartz Inclusions
Aphanitic Porphyritic Basalt
Granite
Phaneritic Felsic Igneous Rock (Granite)
Basalt (River Rock Cobble)
Extrusive mafic volcanic rock (Basalt)
Basalt Pebble
Extrusive mafic igneous rock; primarily (Ca, Na)(Mg, Fe, Al)Si2O6 and (Ca, Na)AlSi3O8
Basalt
Extrusive mafic igneous rock
Unakite (Tumbled)
Epidotized Granite
Andesite River Stones
Andesite
Basalt
Mafic volcanic rock (Basalt)
Basalt with Scoria
Mafic Volcanic Rock (Basalt/Scoria)
Pink Granite
Granite (Phaneritic intrusive igneous rock dominated by Quartz and K-Feldspar)
Unakite
Epidotized Granite
Granite
Intrusive igneous rock (SiO2 range 65-75%)
Basalt with Iron Oxidation
Mafic Igneous Basalt
Basalt (River Pebble)
Extrusive mafic igneous rock
Sandstone (Picture Sandstone)
Sandstone (primarily Quartz with Iron Oxide impurities)
Serpentinite
Serpentinite (composed primarily of mineral group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4)
Basalt (Weathered/River worn)
Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)
Basalt (Road Gravel)
Aphanitic mafic volcanic rock (various compositions of plagioclase feldspar and pyroxene)
Vesicular Basalt
Basalt (Extrusive Igneous Rock)
Limestone with Calcite Veins
Sedimentary Calcium Carbonate (CaCO3)
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Basalt (Polished pebble)
Basalt (Aphanitic mafic volcanic rock)
Serpentine
Serpentine-group (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Sandstone
Arenite (primarily SiO2)
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
Sandstone (Ferruginous Concretion)
Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement
Copper-bearing Quartz (likely Chrysocolla or Malachite staining)
Cuprite, Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O) or Malachite staining on Quartz/Host Rock