Corundum (Sapphire in Host Rock)
Corundum (Aluminum Oxide, Al2O3)
Category
Browse igneous and metamorphic derivative (weathered) specimens identified by the Rock Identifier community.
Corundum (Sapphire in Host Rock)
Corundum (Aluminum Oxide, Al2O3)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Granite
Granite
Plagioclase Feldspar (specifically Albite/Oligoclase)
(Na,Ca)(Si,Al)4O8
Basalt with Scoria
Amygdaloidal Basalt / Vesicular Basalt
Quartzite
Quartzite (primarily SiO2)
Pyrite
Iron Pyrite (FeS₂)
Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Basalt with Limonite stains
Extrusive mafic igneous rock; Limonite (FeO(OH)·nH2O)
Granite (Pink/Red variety)
Phaneritic Felsic Intrusive Igneous Rock (composed primarily of Quartz, K-Feldspar, and Plagioclase)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2)
Basalt with Iron Oxidation (Lattice/Veined)
Mafic Volcanic Rock (principally Plagioclase and Pyroxene)
Heliotrope (Bloodstone)
Cryptocrystalline Quartz (SiO2) with inclusions of Hematite (Fe2O3)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Amethyst (Chevron or Banded Amethyst)
Silicon Dioxide (SiO2) with trace Iron (Fe)
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Smoky Quartz
Silicon Dioxide (SiO2)
Potassium Feldspar
Orthoclase (KAlSi3O8)
Pyrite
Pyrite (FeS2)
Quartzite Pebble
Quartzite (primarily SiO2)
Grey Quartzite Pebble
Quartzite (primarily SiO2 - Silicon Dioxide)
Basalt
Basalt (Fine-grained extrusive igneous rock)
Basalt
Basalt (Mafic Aphanitic Igneous Rock)
Basalt
Basalt (Phaneritic/Aphanitic Mafic Igneous Rock)
Quartz (Tumbled)
Silicon Dioxide (SiO2)
Granite
Phaneritic Intrusive Igneous Rock (composed of Quartz, Feldspar, and Mica)
Porphyritic Basalt (with Amygdales)
Amygdaloidal Porphyritic Basalt
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
Ocean Jasper
Orbicular Jasper/Microcrystalline Quartz (SiO2)
Green Jasper
Silicon Dioxide (SiO2) with mineral inclusions
Sandstone
Clastic sedimentary rock (primarily SiO2)
Limonite
Limonite (Hydrous iron oxides, predominantly Goethite FeO(OH)·nH2O)
Limonite (Iron Ore)
Goethite and related iron hydroxides (FeO(OH)·nH2O)
Limonite (Iron Ore)
Limonite (Hydrated iron oxide - FeO(OH)·nH2O)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Basalt
Basalt (dominated by plagioclase feldspar and pyroxene minerals)
Basalt (Vesicular)
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Mafic volcanic rock (Primary minerals: Plagioclase feldspar, Pyroxene)
Basalt
Basalt