Amethyst
Silicon Dioxide (SiO2) with iron impurities
Category
Browse igneous rock specimens identified by the Rock Identifier community.
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Blue Sapphire
Corundum (Al2O3) with traces of Iron and Titanium
Quartz Geode
Silicon Dioxide (SiO2)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Banded Agate (Onyx type)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Granite
Granite
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Carnelian Agate
Carnelian (SiO2 with iron oxide impurities)
Green Schist
Greenschist (composed of Chlorite, Actinolite, and Epidote)
Biotite (Black Mica)
Biotite [K(Mg,Fe)3(AlSi3O10)(F,OH)2]
Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)
Gneiss (complex silicate composition)
Gneiss
Gneiss (High-grade Metamorphic Rock)
Clear Quartz
Silicon Dioxide (SiO2)
Gneiss
High-grade metamorphic rock (Gneiss)
Obsidian
Volcanic glass (mainly SiO2)
Amygdaloidal Basalt
Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)
Basalt
Basalt (containing mainly Plagioclase feldspar and Pyroxene)
Amygdaloidal Basalt
Amygdaloidal Basalt (Host rock) with Quartz or Calcite amygdules
Pumice
Pumice (Vesicular volcanic glass)
Bumble Bee Jasper
Volcanic Tuff (mixture of SiO2, CaCo3, S, and As2S3)
Basalt
Basalt (comprising Plagioclase feldspar, Pyroxene, and Olivine)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Gneiss
High-grade foliated metamorphic rock
Porphyritic Basalt
Porphyritic Basalt (with plagioclase phenocrysts)
Schorl (Black Tourmaline) in Pegmatite
Sodium Iron Aluminum Borosilicate (NaFe3Al6(BO3)3Si6O18(OH)4)
Lapis Lazuli
Na8(Al6Si6O24)S2 (Lazurite is the primary constituent mineral)
Granite
Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8), and Mica)
Porphyritic Basalt (or Porphyry)
Porphyritic Basalt (Mafic volcanic rock with phenocrysts)
Smoky Quartz
Silicon Dioxide (SiO2)
Quartz Crystal (specifically a small Clear Quartz point)
Silicon Dioxide (SiO2)
Quartz Pebble (Milky Quartz)
Silicon Dioxide (SiO2)
Carnelian (a variety of Chalcedony)
SiO2 (Silicon Dioxide with Iron Oxide impurities)
Quartz (Pebble)
Quartz (SiO₂)
Biotite (Mica)
Biotite group (K(Mg,Fe)3AlSi3O10(F,OH)2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Basalt
Basalt
Basalt
Basalt
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Metasedimentary or Igneous matrix
Quartz Vein in Gneiss or Basalt
Milky Quartz (SiO2) within Metamorphic Host Rock
Scoria (with Iron Oxidation)
Vesicular Basalt / Scoria