Chert (specifically Jasper or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Chert (specifically Jasper or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Concrete
Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)
Dyed and Metallic Coated Agate Geode
Silicon Dioxide (SiO2) with titanium/gold vapor deposition coating
Pumice
Vesicular Rhyolite or Dacite Pumice (Amorphous volcanic glass)
Quartz
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
Quartz
Quartz (SiO₂)
Basalt
Basalt (Mafic volcanic rock)
Diorite (Dalmatian Stone)
Phaneritic Plutonic Diorite
Basalt with Iron Oxidation
Extrusive Mafic Igneous Rock (composed of Plagioclase and Pyroxene)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Limestone
Calcium Carbonate (CaCO3)
Pallasite Meteorite
Pallasite (Stony-iron meteorite; Fe-Ni alloy with (Mg,Fe)2SiO4 olivine)
Granite
Granite (Felsic Intrusive Igneous Rock)
Pink Granite
Phaneritic Plutonic Felsic Rock (Granite)
Basalt Pebble
Extrusive mafic igneous rock
Basalt (River Rock Cobble)
Extrusive mafic volcanic rock (Basalt)
Basalt
Mafic volcanic rock (Basalt)
Pumice
Vesicular volcanic glass
Pumice
Pumicite
Chert (specifically Flint or Jasper variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
White Quartz
Quartz (SiO2)
Chert (specifically a flint nodule component)
Microcrystalline quartz (SiO2)
Basalt
Basalt (Mafic volcanic rock)
Chrysoprase
Chrysoprase (a variety of Chalcedony, SiO₂)
Basalt
Basalt (composition predominately Plagioclase feldspar and Pyroxene)
Chert (specifically Flint or Jasper variant)
Silicon Dioxide (SiO2)
Shale
Fissile mudstone (rich in clay minerals and quartz)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
Amber
Fossilized tree resin (not a true mineral as it is organic and amorphous); Chemical formula is highly variable, but often approximated as C10H16O.
Milky Quartz
Silicon Dioxide (SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Pumice
Vesicular volcanic glass (primarily SiO2)
Basalt with Secondary Mineral Inclusions
Amygdaloidal Basalt (Mafic volcanic rock, primarily Augite and Plagioclase)
Basalt River Pebble
Basalt (Mafic volcanic rock)
Basalt
Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)
Banded Agate (specifically Lake Superior Agate style)
Silicon Dioxide (SiO2) - Chalcedony variety
Sandstone (Greywacke)
Sandstone (SiO2 enriched with lithic fragments)
Chert / Chalcedony (likely carnelian or flint variety)
Silicon Dioxide (SiO2)
Basalt
Basalt (Mafic volcanic rock)
Basalt
Basalt (Mafic volcanic rock)
Pumice
Pumice (Vitreous pyroclastic rock)