Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Category
Browse mineral variant specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Chert (Green and Black Jasper variant)
Cryptocrystalline Quartz (SiO2)
Granite
Felsic intrusive igneous rock
Mahogany Obsidian
Volcanic Glass (High-silica Rhyolite)
Crushed Stone (Likely Granite or Diabase)
Intrusive Igneous Rock (Granitoid/Gabbroid)
Greenstone / Serpentinite
Serpentinite (composed primarily of serpentine minerals: Mg3Si2O5(OH)4)
Granite
Granite (Felsic Plutonic Rock)
Orthoclase Feldspar
Orthoclase (KAlSi₃O₈)
Atlantic Calico Scallop (Biogenic Aragonite/Calcite)
Argopecten gibbus (Chemical: CaCO3)
Chert Pebble (Jasper variety)
Microcrystalline Quartz (SiO2)
Chrysocolla
Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O
Satin Spar (Selenite variant)
Gypsum (Calcium Sulfate Dihydrate, CaSO4·2H2O)
Red Jasper with Fossils
Silicified Fossiliferous Jasper (Chert variant, SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Serpentine
Hydrous magnesium iron silicate, (Mg,Fe)3Si2O5(OH)4
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
River Cobble (Quartzite-rich Sandstone)
Clastic Sedimentary Rock (Litharenite/Quartzite transition)
Quartz (Citrine or Smoky variant)
Silicon Dioxide (SiO2)
Sandstone Concretion
Clastic Sedimentary Rock - Quartz Arenite / Sandstone
Chert (Brown Variety)
Microcrystalline quartz (SiO2)
Chert Pebble
Silicon dioxide (SiO2)
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Diamond
Carbon (C)
Ocean Jasper
Orbicular Jasper (Silicon Dioxide, SiO2)
Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
Quartz Geode
Silicon Dioxide (SiO2)
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Sandstone (Greywacke/Siltstone variant)
Arenite / Wacke (SiO2 with diverse mineral inclusions)
Chert
Microcrystalline Quartz (SiO2)
Sandstone (likely Greywacke variant)
Arenite
Jasper (Petrified Wood variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Feldspar (specifically Orthoclase)
Potassium Aluminum Silicate (KAlSi3O8)
Serpentinite
Serpentinite (composed largely of serpentine group minerals including Antigorite, Lizardite, or Chrysotile)
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Chalcedony (Agate/Carnelian variant)
Cryptocrystalline Silica (SiO2)
Quartz (Milky or Smoky variant)
Silicon Dioxide (SiO2)
Quartz (Milky/Common variant)
Silicon Dioxide (SiO2)
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)