Porphyritic Basalt (Chinese Writing Stone)
Porphyritic Basalt or Porphyritic Andesite
Category
Browse anthropogenic material (man made rock) specimens identified by the Rock Identifier community.
Porphyritic Basalt (Chinese Writing Stone)
Porphyritic Basalt or Porphyritic Andesite
Quartzite
Quartzite (SiO2)
Schist
Mica Schist (primarily Muscovite [KAl2(AlSi3O10)(OH)2] or Biotite)
River Rocks (Polished River Pebbles)
Stream-rounded clastic sediments
Ferruginous Conglomerate
Conglomerate with Iron-Oxide Matrix (SiO2 + Fe2O3/FeO(OH))
Chert / Pink Chert
Silicon Dioxide (SiO2)
Coquina or Fossilized Shell Fragment
Calcium Carbonate (CaCO3) / Biogenic Limestone
Pumice
Pumice (Amorphous volcanic glass)
Magnetite (Lodestone)
Iron(II,III) oxide (Fe3O4)
Chert (Yellow/Brown Jasper)
Silicon Dioxide (SiO2)
Sandstone (Ferruginous/Banded)
Clastic Terrigenous Sandstone (SiO2 with Fe2O3 cement)
Basalt
Basalt
Dyed Agate
Silicon Dioxide (SiO2) - variety Chalcedony
Granite
Granite (Phaneritic intrusive igneous rock)
Quartzite
Quartzite (composed primarily of SiO2)
Quartzite
Metamorphosed Quartz Sandstone
Banded Chert (or Flint)
Microcrystalline Quartz (SiO2)
Jasper Breccia
Brecciated Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
Sandstone (Quartz-rich Pebble)
Arenite (primarily SiO2)
Sandstone
Arenite
Sandstone
Arenite (composed primarily of SiO2)
Basalt with Peridotite Inclusion
Mafic Volcanic Rock (Extrusive Igneous) with Ultramafic Xenolith
Petrified Wood
Silicified Wood (SiO2)
Banded Agate (specifically Carnelian Agate)
Silicon dioxide (SiO2) - Chalcedony variety
Sandstone (Ferruginous)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 cement)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Pyrite (on host rock)
Iron Sulfide (FeS2)
Ironstone Concretion / Goethite-Hematite Nodule
Goethite/Hematite (α-FeO(OH) / Fe2O3)
Laterite
Laterite (Iron and aluminum-rich residual rock)
Red Chert (Jasper)
Silicon Dioxide (SiO2)
Chert Pebble
Chert (composed primarily of Microcrystalline Quartz, SiO2)
Slate
Slate (Low-grade foliated metamorphic rock)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Granite
Granite (felsic intrusive igneous rock)
Basalt
Basalt (a mafic extrusive igneous rock)
Conglomerate (River Rock Aggregate)
Conglomerate (Lithic-clast conglomerate)
Basalt
Basalt
Granodiorite Pebble
Granodiorite (containing Quartz, Plagioclase Feldspar, and Biotite/Amphibole)
Serpentine
Serpentinite (rock) containing serpentine minerals (e.g., Antigorite, Lizardite, Chrysotile)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Limonite (Yellow Ochre)
FeO(OH)·nH2O (Hydrous iron(III) oxide-hydroxide mixture)