Scoria
Scoria (vesicular basalt-andesite)
Category
Browse man made specimens identified by the Rock Identifier community.
Scoria
Scoria (vesicular basalt-andesite)
Basalt with Weathering Crust
Extrusive mafic volcanic rock
Black Obsidian
Volcanic Glass (predominantly SiO2)
Citrine Quartz
Silicon Dioxide (SiO2) with iron impurities
Feldspar (specifically Orthoclase or Plagioclase)
Potassium Aluminum Silicate (KAlSi3O8) or Sodium/Calcium Aluminum Silicate
Citrine
Citrine (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Small Pebble)
Silicon Dioxide (SiO2)
Chert (Basanite / Jasperoid)
Microcrystalline Quartz (SiO2)
Citrine Quartz Sphere
Silicon Dioxide (SiO2)
Mica Schist
Mica Schist (primarily muscovite and biotite)
Chert / Flint
Chert (Cryptocrystalline Quartz, SiO2)
Fossilized Coral (Petoskey Stone or Rugose Coral)
Antophyllum (Hexagonaria) or Scleractinia (CaCO3)
Granite
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
Milky Quartz
Silicon Dioxide (SiO2)
Agate (Dyed High-Grade Polished Slice)
Silicon dioxide (SiO2), Chalcedony crystal variety
Sandstone (with minor quartz and possible clay components)
Clastic Sedimentary Rock (SiO2 dominated)
Basalt River Pebble
Extrusive mafic igneous rock
Basalt River Stone
Aphanitic Basalt
Sandstone
Arenite (composed primarily of SiO2)
Sandstone
Arenite (primarily SiO2)
Vesicular Basalt
Vesicular Basalt (Mafic Volcanic Rock)
Granite
Granite (Felsic Plutonic Rock)
Gold Nugget
Native Gold (Au)
Limonite pseudo-concretion (Ironstone)
Limonite (FeO(OH)·nH2O) / Goethite
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Citrine or Yellow Quartz
Silicon Dioxide (SiO2) with iron impurities
Greenstone
Greenschist-facies basaltic rock
Sandstone (Quartzite-rich)
Clastic sedimentary rock (primarily SiO2)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Gneiss
Gneiss (High-grade metamorphic rock)
Pebble (likely Quartz or Chert)
SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.
Red Sandstone
Ferruginous Sandstone (SiO2 with Fe2O3)
Quartz (Smoky/Milky variant)
Silicon Dioxide (SiO2)
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Basaltic Tuff / Volcanic Breccia
Pyroclastic Breccia / Lithic Tuff
Basalt (River Rock pebble)
Basalt (a mafic extrusive igneous rock)
Peacock Ore
Bornite (Cu5FeS4)
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Jasper or Chert
Silicon Dioxide (SiO2)
Smoky Quartz Geode
Silicon Dioxide (SiO2)