Pumice
Vesicular volcanic glass (primarily SiO2)
igneous
Category
Sedimentary (Volcanic)
Browse sedimentary (volcanic) specimens identified by the Rock Identifier community.
Scoria (Vesicular Basalt)
Vesicular Basaltic Andesite
igneous
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
sedimentary
Basalt (Weathered River Stone)
Basalt (Extrusive Mafic Igneous Rock)
igneous
Basalt
Extrusive mafic igneous rock
igneous
Olivine
Olivine group (Mg, Fe)2SiO4
mineral
Basalt (with possible iron oxide staining)
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Rhyolite Pebble
Rhyolite
igneous
Basalt with Jasper Veining
Basaltic Rock with Cryptocrystalline Quartz (SiO2)
igneous
Grey Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
mineral
Basalt
Basalt
igneous
Basalt (River Stone/Pebble)
Basalt (Extrusive Igneous Rock)
igneous
Olivine (Peridot when gem-quality)
Olivine Group (Magnesium Iron Silicate, (Mg,Fe)2SiO4)
mineral
Vesicular Basalt
Extrusive Basalt (Mafic Silicate)
igneous
Diorite (Porphyritic)
Porphyritic Diorite
igneous
Basalt River Stone
Basalt (Aphanitic Mafic Igneous Rock)
igneous
Vesicular Basalt with Quartz/Chalcedony
Vesicular Basalt (primarily Plagioclase, Pyroxene, and Olivine with SiO2 infill)
igneous
Plagioclase Feldspar
Plagioclase Feldspar Series (NaAlSi3O8 - CaAl2Si2O8)
Mineral
Vesicular Basalt
Basalt (principally Plagioclase and Pyroxene)
igneous
Basalt
Basalt
igneous
Vesicular Basalt (Scoria)
Basalt (Vesicular)
igneous
Sandstone
Arenite (Sedimentary Rock)
sedimentary
Porphyritic Basalt
Porphyritic Basalt (Mafic extrusive rock)
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt (containing secondary minerals like Quartz, Zeolites, or Calcite)
igneous
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Igneous
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Basalt with Peridotite Inclusion
Mafic Volcanic Rock (Extrusive Igneous) with Ultramafic Xenolith
igneous
Conglomerate
Conglomerative Sedimentary Rock
sedimentary
Conglomerate (or Breccia)
Clastic Sedimentary Rock
sedimentary
Sandstone (likely Graywacke or Lithic Sandstone)
Clastic Sedimentary Rock
sedimentary
Limestone
Sedimentary Calcite (CaCO3)
sedimentary
Conglomerate
Conglomerate (Sedimentary rock)
sedimentary
River Pebble (Siltstone/Mudstone)
Clastic sedimentary rock
sedimentary
River Rock (likely Siltstone or fine-grained Sandstone)
Clastic Sedimentary Rock
sedimentary
Conglomerate
Clastic sedimentary conglomerate
sedimentary
Shale
Lutaceous Sedimentary Rock
sedimentary
Jasper and Aquamarine (likely)
Jasper (Cryptocrystalline Quartz (SiO2)), Aquamarine (Beryl (Be3Al2Si6O18))
Sedimentary (Jasper), Mineral (Aquamarine)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous
Snowflake Obsidian
Vitreous Volcanic Glass (Siliceous Obsidian with Cristobalite inclusions)
igneous
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
igneous
Amygdaloidal Rhyolite
Rhyolite (felsic volcanic rock) with amygdules
igneous
Gastropod Fossil (Internal Mold)
Phylum Mollusca, Class Gastropoda (Steinkern)
sedimentary