Basalt
Mafic Volcanic Rock
igneous
Category
Sedimentary (Volcanic)
Browse sedimentary (volcanic) specimens identified by the Rock Identifier community.
Basalt
Basalt (Extrusive Mafic Igneous)
igneous
Basalt
Mafic Volcanic Rock (composed of plagioclase, pyroxene, and olivine)
igneous
Pumice
Pumice (Vesicular volcanic glass)
Igneous
Andesite
Intermediate Volcanic Rock (Andesite)
igneous
Ocean Jasper (Orbicular Jasper)
Silicon Dioxide (SiO2) - Variety of Chalcedony/Quartz
mineral
Green Porphyry (Flowerstone)
Porphyritic Andesite or Basalt
igneous
Ocean Jasper
Silicon Dioxide (SiO2)
Mineral_variety_of_Chalcedony
Basalt (Vesicular or Porphyritic)
Basalt (composed primarily of plagioclase feldspar, pyroxene, and olivine)
igneous
Porphyritic Basalt
Basalt (with plagioclase phenocrysts)
igneous
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
mineral
Botryoidal Chalcedony (Desert Rose / Grape Agate variant)
Silicon Dioxide (SiO2)
mineral
Basalt (River Cobble)
Mafic Igneous Basalt (composed primarily of Plagioclase feldspar, Pyroxene, and Olivine)
Igneous
Sandstone (Quartzite-rich)
Clastic sedimentary rock (SiO2 primary)
sedimentary
Banded Jasper
Silicon Dioxide (SiO2)
Mineral/Sedimentary Rock (as a cryptocrystalline variety of quartz)
Fancy Jasper
Chalcedony (cryptocrystalline quartz) with inclusions
Mineral
Andesite River Stones
Andesite
igneous
Sandstone
Arenite
sedimentary
Brown Sandstone
Arenite (primarily Quartz and Feldspar, with Iron Oxide cement)
sedimentary
Ferruginous Sandstone
Arenite with Iron-Oxide cement (Fe2O3 · nH2O)
sedimentary
Ocean Jasper (Orbicular Jasper)
Silicon Dioxide (SiO2) with various inclusions
sedimentary (geologically classified as a variety of chalcedony/quartz)
Celadonite in Amygdaloidal Basalt
K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2 (Celadonite mineral) within a Basalt matrix
igneous
Porphyritic Basalt (likely Chinese Writing Stone)
Porphyritic Basalt / Plagioclase Feldspar in Basal Matrix
igneous
Moss Agate
Silicon Dioxide (SiO2) with inclusions of manganese or iron oxides
Mineral (Variety of Chalcedony)
Stilbite
Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O)
mineral
Tree Agate (Dendritic Agate)
Silicon Dioxide (SiO2) with Manganese/Iron inclusions
mineral
Scoria
Vesicular Basalt / Scoriaceous Basalt
igneous
Andesite Porphyry
Porphyritic Andesite
igneous
Black Onyx
Silicon dioxide (SiO2) - Chalcedony variety
mineral
Orbicular Jasper (Ocean Jasper)
Silicon Dioxide (SiO2) with iron and magnesium inclusions
mineral
Crazy Lace Agate
Agate (Cryptocrystalline Quartz), Silicon Dioxide (SiO2)
mineral
Basalt (Weathered)
Extrusive mafic volcanic rock
igneous
Basalt
Basalt (composition of plagioclase feldspar and pyroxene)
Igneous
Basalt
Mafic Igneous Rock
igneous
Banded Agate Geode
Silicon Dioxide (SiO2)
mineral
Pumice
Pumice (volcanic glass formed of highly vesicular rough textured rock)
igneous
Shale
Lutaceous sedimentary rock
sedimentary
Peridot in Basalt/Xenolith
Olivine (Mg, Fe)2SiO4 in Vesicular Basalt
igneous
Basalt Pebble
Basalt
igneous
Olivine (Peridot)
Olivine (Mg, Fe)2SiO4
mineral
Basalt
Basalt (Mafic igneous rock)
igneous
Peridot
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
mineral