Basalt
Basalt (Mafic volcanic rock)
igneous
Category
Igneous Rock (Volcanic Glass)
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
Diorite
Diorite (an intrusive igneous rock)
igneous
Green Porphyry (Flowerstone)
Porphyritic Andesite or Basalt
igneous
Basalt (with possible iron oxide staining)
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
sedimentary
Amygdaloidal Basalt
Vesicular Basalt with secondary mineral infilling (commonly Zeolites, Calcite, or Quartz)
igneous
Dark Igneous Rock (Likely Basalt or Diabase)
Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.
Igneous
Basalt (Weathered River Stone)
Basalt (Extrusive Mafic Igneous Rock)
igneous
Vesicular Basalt with Secondary Mineral Inclusions
Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Basalt
Basalt (extrusive volcanic mafic rock)
igneous
Massive Quartz with Host Rock
Silicon Dioxide (SiO2)
mineral
Basalt (Vesicular)
Extrusive Mafic Igneous Rock
igneous
Scoria (Lava Rock)
Vesicular Basalt / Scoria
igneous
Greenstone / Epidosite
Epidosite (Metasomatic rock consisting mainly of Epidite Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH) and Quartz)
metamorphic
Basalt River Pebble
Basalt (fine-grained mafic igneous rock)
igneous
Banded Agate (specifically Carnelian Agate)
Silicon dioxide (SiO2) - Chalcedony variety
mineral
Basalt (River Stone/Pebble)
Basalt (Extrusive Igneous Rock)
igneous
Basalt (Water-worn Pebble)
Mafic Volcanic Rock (High in Fe and Mg)
igneous
Basalt
Basalt
igneous
Basalt
Extrusive mafic igneous rock
igneous
Basalt
Extrusive mafic igneous rock
igneous
Scoria (Lava Rock)
Vesicular Basalt / Scoria
igneous
Quartz Vein Rock
Quartz (Silicon Dioxide, SiO2)
igneous
Basalt
Basalt (composition of Plagioclase feldspar and Pyroxene)
igneous
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Quartz (Druzy on Matrix)
Silicon Dioxide (SiO2)
mineral
Porphyritic Basalt (or Andesite) Pebble
Porphyritic Mafic Volcanic Rock
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive volcanic rock)
igneous
Andesite
Andesite (Intermediate Volcanic Rock)
igneous
Snowflake Obsidian
Spherulitic Obsidian (primarily SiO2 with Cristobalite inclusions)
igneous
Basalt with Calcite Veining
Aphanitic Mafic Igneous Rock (Basalt) with CaCO3
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Dacite
Dacite (Intermediate volcanic rock)
igneous
Dalmatian Stone (commonly Dyed)
Dalmatian Jasper (Peralkaline igneous rock)
igneous
Snowflake Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Basalt (River Rock Cobble)
Extrusive mafic volcanic rock (Basalt)
igneous
Basalt (River Pebble)
Basalt (Aphanitic Mafic Volcanic Rock)
igneous
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive)
igneous
Basalt (River Pebble)
Extrusive Mafic Igneous Rock
igneous