Basalt
Basalt (Mafic volcanic rock)
Category
Browse mineral in igneous rock specimens identified by the Rock Identifier community.
Basalt
Basalt (Mafic volcanic rock)
Basalt (River Pebble)
Basalt (extrusive mafic rock)
Andesite
Andesite (intermediate volcanic rock)
Granite
Granite (Felsic Plutonic Rock)
Basalt
Mafic volcanic rock (Basalt)
Basalt
Basalt (Mafic volcanic rock)
Pink Granite
Granite (Felsic Plutonic Rock)
Pink Granite
Granite (Felsic Plutonic Rock)
Apache Tears (Obsidian)
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Granite Cobble
Plutonic Granite
Apache Tear
Obsidian (Hydrated Silica Rich Volcanic Glass)
Apache Tear
Obsidian (Hydrated Volcanic Glass) - SiO2 (with impurities)
Scoria
Vesicular Basalt / Scoria
Quartzite (river pebble) and Gabbro (crushed rock)
Quartzite (metamorphosed Quartz Sandstone, SiO2) and Gabbro (Plagioclase-Clinopyroxene rock)
Quartz (Milky or Cloudy Quartz)
Silicon Dioxide (SiO2)
Lapis Lazuli (Tumbled Specimen)
Lapis Lazuli (Aggregate rock containing Lazurite: (Na,Ca)8(AlSiO4)6(SO4,S,Cl)2)
Sandstone (with Concretion)
Arenite / Quartzose Sandstone
Banded Gneiss
Gneiss (High-grade metamorphic rock typically composed of Quartz, Feldspar, and Mica)
Basalt
Basalt (containing plagioclase, pyroxene, and olivine)
Basalt
Basalt
Decomposed Granite
Grano-diorite/Granite-residuum (SiO2 primary)
River Rock (Basalt)
Basalt (SiO2 range: 45-52%)
Druzy Quartz on Chert/Siltstone
Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Limonite (Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Gneiss (with Quartz and Mica)
Gneiss
Garnet (likely Almandine or Pyrope)
Garnet Group (e.g., Almandine: Fe3Al2(SiO4)3; Pyrope: Mg3Al2(SiO4)3)
Gneiss (likely)
Gneiss
Basalt
Basalt
Basalt
Basalt
Basalt
Basalt (Mafic Extrusive)
Basalt
Basalt
Massive Quartz (Milky or Gray)
Silicon Dioxide (SiO2)
Amethyst
Quartz (SiO2) with trace iron impurities
Pumice
Pumice (volcanic glass foam)
Porphyritic Basalt
Porphyritic Basalt (containing Plagioclase or Alkali Feldspar phenocrysts)
Basalt (Vesicular or Porphyritic)
Basalt (composed primarily of plagioclase feldspar, pyroxene, and olivine)
Basalt
Basalt (composition mainly of Plagioclase feldspar, Pyroxene, and Olivine)
Pumice
Pumice (a highly vesicular volcanic rock)
Andesite
Andesite
Pumice
Pumice (Vesicular volcanic glass)
Crushed Granite Gravel
Granite (composed primarily of Quartz, Alkali Feldspar, and Plagioclase Feldspar)