Basalt
Extrusive mafic igneous rock
Category
Browse metamorphic rock specimens identified by the Rock Identifier community.
Basalt
Extrusive mafic igneous rock
Quartz Veinated Sandstone or Siltstone
Silicon Dioxide (SiO2) within a clastic sedimentary matrix
Basalt
Basalt (Mafic igneous rock)
Milky Quartz with Mineral Inclusions
Silicon Dioxide (SiO2) with miscellaneous inclusions
Milky Quartz Pebble (Iron-Stained)
Silicon Dioxide (SiO2)
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Limonite streaks)
Sandstone (Quartzite Pebble)
Arenite (primarily SiO2)
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
White Quartz
Silicon Dioxide (SiO2)
Blue Dyed Agate Geode
Chalcedony (cryptocrystalline Quartz), SiO2
Muscovite Mica in Quartz Matrix
Muscovite (KAl2(AlSi3O10)(OH)2) in Quartz (SiO2)
Blue Aventurine
Silicon Dioxide (SiO2) with inclusions of Dumortierite
Muscovite (Mica) in Quartz Matrix
Muscovite (KAl2(AlSi3O10)(OH)2) and Quartz (SiO2)
Granodiorite Pebble
Granodiorite
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Sandstone
Arenite
Basalt (River Rock Cobble)
Extrusive mafic igneous rock
Sapphire
Corundum (Al2O3)
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
Sandstone
Arenite (SiO2 primarily)
Petoskey Stone
Hexagonaria percarinata
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with iron oxide and other mineral impurities
Jasper
Jasper (Silicon Dioxide, SiO2)
Jasper (Multi-color Chert)
Silicon dioxide (SiO2)
Jasper
Silicon dioxide (SiO2) with impurities
Sandstone
Arenite (primarily SiO2)
Sandstone (Pebble)
Arenite (composed primarily of SiO2)
Bivalve Fossil (Shell Fragment)
Class Bivalvia (Calcium Carbonate - CaCO3)
Moss Agate
Chalcedony (Silicon Dioxide) with dendritic inclusions (SiO2)
Kimberlite with Diamond
Kimberlite (Porphyritic Peridotite)
Sandstone
Arenite (SiO2 principal component)
Jasper pebble
Silicon dioxide (SiO2) with iron oxide inclusions
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Plume Agate
Silicon Dioxide (SiO2)
Limestone
Calcareous sedimentary rock (CaCO3)
Graphite
Graphite (Chemical Formula: C)
Epidote
Epidote (Ca2(Al,Fe)3(SiO4)3(OH))
Jade (likely Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Sandstone
Arenite (composed primarily of SiO2)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Quartz (Milky/Crystalline variety)
Silicon Dioxide (SiO2)