Obsidian Arrowhead
Volcanic Glass (SiO2)
Category
Browse industrial byproduct (anthropogenic rock like material) specimens identified by the Rock Identifier community.
Obsidian Arrowhead
Volcanic Glass (SiO2)
Quartz (Yellow/Citrine variety or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Limestone with Iron Inclusions
Calcium Carbonate (CaCO3) with Hematite/Limonite
Yellow Chert
Microcrystalline Quartz (SiO2)
Mica Schist
Metamorphic rock dominated by muscovite and/or biotite mica
Sandstone
Arenite (composed primarily of SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Chert Nodule (Commonly known as Flint or River Rock)
Silicon Dioxide (SiO2)
Vesicular Basalt (commonly mistaken for Slag)
Scoriaceous Basalt (composed primarily of Plagioclase Feldspar and Pyroxene)
Sandstone (likely Graywacke or Lithic Sandstone)
Clastic Sedimentary Rock
Blue Cat's Eye Quartz (Heated/Dyed)
Silicon Dioxide (SiO2) with fibrous inclusions
Granite
Phaneritic plutonic igneous rock (typically 20% to 60% quartz by volume)
Chert (and Jasper) Nodules in Limestone
Silicon Dioxide (SiO2) microcrystalline quartz
Sandstone
Arenite (composed primarily of SiO2)
Pumice
Pumice (a highly vesicular volcanic glass)
Note: No specimen visible
Vesicular Basalt (Scoria)
Basalt (Extrusive Igneous Rock)
Chert (Jasper/Chalcedony Pebble)
Silicon Dioxide (SiO2)
Amethyst (purple quartz)
Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
Basalt (Greenstone)
Mafic volcanic rock (Basalt)
Basalt
Basalt (Mafic volcanic rock)
Granite
Granitic intrusive igneous rock
Quartzite Pebble
Quartzite (SiO2)
Serpentinite
Serpentinite (composed primarily of minerals in the serpentine group: (Mg,Fe)3Si2O5(OH)4)
Anthracite Coal
Low-grade metamorphic carbonaceous rock
Orbicular jasper (orbicular chert), likely ocean jasper
Silicified microcrystalline quartz (chalcedony), SiO₂, with iron-oxide and/or clay-rich orbicules
Sandstone (Quartzose)
Arenite (SiO2 principal)
Likely weathered quartz-rich stone
Indeterminate; possibly quartz-bearing granite or milky quartz
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
Sandstone (with Limonite staining)
Arenite (primarily SiO2 with FeO(OH)·nH2O)
Pyrite
Iron Sulfide (FeS2)
Sandstone
Arenite/Quartz Arenite
Banded Gneiss (River Cobble)
Gneiss (a high-grade metamorphic rock)
Blue Sapphire
Corundum (Al2O3 with iron and titanium trace elements)
Sedimentary Breccia
Breccia (Clastic Sedimentary Rock)
Chert
Silicon dioxide (SiO2)
Sandstone
Quartz Arenite / Clastic Sedimentary Rock
Diorite
Intermediate plutonic igneous rock
Sandstone with Iron Oxide
Arenite (SiO2 with Fe2O3 inclusions)
Red Sandstone
Sandstone (Quartz Arenite with Iron Oxide)
Quartz geode
Quartz (SiO₂), likely drusy/microcrystalline quartz lining a geode cavity