Basalt
Mafic Igneous Basalt
Category
Browse mineral like byproduct (often mistaken for igneous rock or meteorite) specimens identified by the Rock Identifier community.
Basalt
Mafic Igneous Basalt
Pumice
Pumice (Vesicular volcanic glass)
Serpentinite
Serpentinite (composed largely of serpentine group minerals including antigorite, lizardite, and chrysotile)
Clear Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2)
Sandstone (Quartz Sandstone)
Arenite (primarily SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 based)
Vesicular Basalt with Pyrite
Basalt (MgFe2+)(Si,Al)2O6 containing FeS2 inclusions
Crushed Granite and Quartz Gravel
Composite Igneous and Silicate Rock Aggregate
Porphyry
Porphyritic Igneous Rock
Basalt
Basalt (extrusive volcanic rock)
Red Sandstone
Ferruginous Sandstone (SiO2 with Fe2O3)
Beach Pebble (Basalt/Greywacke)
Amygdaloidal Basalt
Quartz
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2) in a Geode body
Pink Granite
Granite (Felsic Plutonic Rock)
Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
Septarian Nodule
Septarian Concretion (Calcite, Aragonite, and Limestone)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Basalt River Pebble
Basalt (Aphanitic Mafic Volcanic Rock)
Sandstone
Arenite (SiO2 based)
Quartz (Milky/Tan)
Silicon Dioxide (SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Banded Gneiss
Gneiss (Metamorphic Rock)
Blue Quartz
Quartz (Silicon Dioxide) with blue inclusions (SiO2)
Gold-bearing Quartz with Iron Oxides
Quartz (SiO2) with Limonite/Goethite (FeO(OH)) and Pyrite (FeS2)
Sandstone
Arenite (SiO2 based with various mineral cements)
Rhyolite
Rhyolite (felsic volcanic rock)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
Diorite
Diorite (Intermediate intrusive igneous rock)
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Basalt Pebble
Basalt
Jasper in Calcite / Brecciated Jasper
Silicon dioxide with calcium carbonate (SiO2 with CaCO3)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz Pebble
Silicon Dioxide (SiO2)
Iron-stained Quartzite / Agate
Silicon Dioxide with Iron Oxides (SiO2 + Fe2O3·nH2O)
Porphyritic Basalt or Lamprophyre
Extrusive igneous rock with visible phenocrysts
Sandstone
Arenite
Gneiss (or Granite Gneiss)
Metamorphic rock rich in quartz, feldspar, and biotite/amphibole