Arkosic Sandstone (or Conglomeritic Sandstone fragment)
Arkose (rich in feldspar)
Category
Browse igneous rock specimens identified by the Rock Identifier community.
Arkosic Sandstone (or Conglomeritic Sandstone fragment)
Arkose (rich in feldspar)
Gneiss (Green Gneiss)
Gneiss (High-grade Regional Metamorphic Rock)
Serpentine
Serpentine Group (primarily Antigorite or Lizardite), Mg3Si2O5(OH)4
Scoria (Red Lava Rock)
Scoria (Vesicular basaltic rock)
Porphyritic Basalt (Leopard Rock)
Porphyritic Mafic Volcanic Rock
Basalt with Quartz/Feldspar Inclusion
Basalt (containing Silicate minerals such as SiO2 and (Ca,Na)(Al,Si)4O8)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Hypersthene
Hypersthene (formula: (Mg,Fe)SiO3)
Milky Quartz Pebble
Crystalline Quartz (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Chrysocolla (on host rock)
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Copper silicate)
Granite Pegmatite with Muscovite Mica
Granite Pegmatite (Silicon Dioxide and complex silicates)
Olivine Basalt
Mafic Volcanic Rock (rich in (Mg, Fe)2SiO4)
Amygdaloidal Basalt with Epidote/Chlorite
Basalt (containing (Ca2(Al2Fe3+)(SiO4)(Si2O7)O(OH)))
Quartz Pebble
Silicon Dioxide (SiO2)
Biotite Mica
K(Mg,Fe)3AlSi3O10(OH)2
Basalt
Basalt (Mafic volcanic rock)
Eudialyte in Matrix
Na15Ca6Fe3Zr3Si26O72(OH,Cl,H2O)3
Basalt with Feldspar phenocrysts
Aphanitic to Porphyritic Mafic Volcanic Rock
Granite
Plutonic Granite
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Basalt River Cobble
Basalt
Scoria (Lava Rock)
Scoria (Vesicular Basalt)
Porphyritic Basalt (with Augite Crystals)
Porphyritic Mafic Volcanic Rock (Fe-Mg Silicates)
Greenschist
Greenschist facies metamorphic rock
Porphyritic Basalt
Aphanitic-porphyritic mafic volcanic rock
Gneiss
Gneiss (High-grade metamorphic rock)
Porphyry
Porphyritic Basaltic Andesite
Labradorite (Larvikite variety)
Plagioclase Feldspar (Na,Ca)(Al,Si)4O8 with Monzonite/Syenite matrix
Porphyritic Basalt or Andesite
Porphyritic Basalt/Andesite
Porphyritic Basalt (Porphyry)
Porphyritic Basalt
Bumblebee Jasper
Volcanic Tuff (mixture of Quartz, Sulfur, Hematite, and Orpiment)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock including secondary mineral infills)
Granite
Granite
Basalt Gravel
Basalt
Granite
Granite
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Diorite
Diorite
Granite
Felsic Plutonic Rock (primarily SiO2, Al2O3, K2O, Na2O)
River Pebble (Gneiss or Quartzite mixture)
Metamorphic rock (Commonly Gneissic)
Vesicular Basalt (River Stone)
Basalt (Aphanitic-Vesicular Mafic Rock)