Basalt River Cobble
Extrusive Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Category
Browse basalt specimens identified by the Rock Identifier community.
Basalt River Cobble
Extrusive Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Porphyritic Basalt
Porphyritic Fine-grained Mafic Volcanic Rock
Basalt (River Rock)
Basalt (Mafic volcanic rock)
Olivine
Magnesium Iron Silicate ((Mg, Fe)₂SiO₄)
Amygdaloidal Basalt
Basalt with secondary mineral infillings (SiO2, (Ca,Na)2-3(Mg,Fe,Al)5Si8O22(OH)2)
Carnelian Agate
Carnelian (Silicon Dioxide - SiO2 with Fe impurities)
Olivine Peridotite
Peridotite (comprising Olivine (Mg,Fe)2SiO4 and Pyroxene)
Grey Agate
Silicon Dioxide (SiO2) - variety: Agate/Chalcedony
Peridot
Olivine ((Mg, Fe)2SiO4)
Diabase (also known as Dolerite)
Diabase
Amethyst
Amethyst (Silicon Dioxide - SiO2 with Iron impurities)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Carnelian Agate
Silicon Dioxide (SiO2)
Diabase (Dolerite)
Diabase
Carnelian
Silicon dioxide (SiO2) with Iron Oxide impurities
Diabase
Diabase (also known as Dolerite)
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Labradorite (Dark or Black variety)
Labradorite (member of Plagioclase Feldspar group), (Na,Ca)(Si,Al)4O8
Carnelian
Carnelian (SiO2)
Greenschist
Greenschist facies rock (containing chlorite, actinolite, and epidote)
Eclogite
Eclogite (Omphacite-Garnet rock)
Weathered Basalt with Iron Staining
Aphanitic Mafic Volcanic Rock
Basalt with Weathering Rind
Basalt (Mafic volcanic rock)
Basalt (River Pebble)
Basalt (Aphanitic Mafic Volcanic Rock)
Magnetite (Iron Ore)
Magnetite (Fe3O4)
River Cobble (likely Basalt or Chert)
Siliceous River Rock / Microcrystalline Quartz / Mafic Igneous
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
Labradorite
Plagioclase Feldspar ((Ca, Na)(Al, Si)4O8)
Labradorite (Gray Tumbled)
Labradorite (Ca,Na)(Al,Si)4O8
Greenstone
Chlorite schist or Epidosite
Actinolite
Ca2(Mg,Fe)5Si8O22(OH)2
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Blue Chalcedony
Silicon Dioxide (SiO2)
River Pebble (Basalt or fine-grained Quartzite)
Fine-grained Mafic Rock (Volcanic Basalt)
Amygdaloidal Basalt
Basalt with secondary mineral infilling
Basalt and Quartz Pebble
Basalt (Igneous) and Quartzite/Quartz (SiO2) pebble
Larimar
Pectolite, NaCa2Si3O8(OH)
Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Red Scoria
Scoria (Basaltic Scoria)
Scoria (Vesicular Basalt)
Vesicular Basaltic Andesite
Peridot (Olivine)
Magnesium Iron Silicate (Mg,Fe)2SiO4