Basalt
Extrusive mafic igneous rock
Category
Browse mineral on igneous rock specimens identified by the Rock Identifier community.
Basalt
Extrusive mafic igneous rock
Quartz
Quartz (SiO₂)
Iron-Stained Quartz (Riverside Cobble)
Silicon Dioxide (SiO2) with Limonite/Hematite inclusions
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and K-feldspar)
Basalt
Basalt
Basalt
Mafic volcanic rock (formula varies by mineral content: Ca-plagioclase, Pyroxene, Olivine)
Granite
Granite
Basalt with Quartz Veins
Amygdaloidal Basalt (matrix) with Crystalline SiO2 (veins)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Gold Ore in Matrix
Native Gold (Au) in Quartz/Host Rock
Serpentinite
Serpentinite (composed primarily of serpentine-group minerals like antigorite, chrysotile, and lizardite; chemical formula varies but generally Mg3Si2O5(OH)4)
Granite Gneiss
Gneiss (high-grade metamorphic rock)
Granitoid (Granite/Granodiorite)
Plutonic igneous rock (variable composition, primarily SiO2)
Granite Cobble (River Stone)
Felsic intrusive igneous rock (composition: Quartz, Feldspar, Mica)
Pink Granite
Granite (Phaneritic igneous rock rich in Alkali Feldspar and Quartz)
Granite
Plutonic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
Quartz (specifically Citrine or Yellow Quartzite pebble)
Silicon Dioxide (SiO2)
Gold Ore
Auriferous Quartz and Sulfide Mineralization in Host Rock
Clear Quartz (or Rock Crystal)
Quartz (SiO₂)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Granitic Pegmatite
Granite (with coarse-grained Quartz, Feldspar, and Mica components)
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)
Quartz Vein in Host Rock (Gabbro or Basalt)
Silicon Dioxide (SiO2) with Mafic Silicates
Vesicular Basalt (Scoria)
Extrusive Mafic Volcanic Rock (FeO-SiO2-MgO)
Yooperlite (Syenite clast containing fluorescent Sodalite)
Sodalite-bearing Syenite
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Gneiss
Gneiss
Quartz / Calcite Vein Rock
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)
Basalt (Vesicular)
Extrusive mafic igneous rock; primarily (Mg, Fe)2SiO4 (Olivine), CaAl2Si2O8 (Plagioclase Feldspar), and Pyroxene
Amethyst (Chevron or Banded Amethyst)
Silicon Dioxide (SiO2) with iron impurities
Granite
Granite (Felsic Plutonic Rock)
Granite
Phaneritic Felsic Igneous Rock (Granite)
André Landed Here Rock (Glacial Erratic)
Granodiorite / Diorite (compositional estimate)
Milky Quartz
Silicon Dioxide (SiO2)
Obsidian
Volcanic glass (high silica volcanic rock)
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Feldspar, and Mica)
Gneiss
Gneiss (High-grade regional metamorphic rock)
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
Magnetite (potentially as a Lodestone or within Ironstone)
Magnetite (Fe3O4)
Granite
Granite (a common rock type, not a single mineral species)
Kimberlite with Diamond
Kimberlite (Porphyritic Peridotite)