Obsidian
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Category
Browse igneous (anthropogenic) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Granite
Granite (Phaneritic Quartz-Feldspar rock)
Orbicular Rhyolite (Rainforest Jasper)
Rhyolite containing Spherulites (SiO2 with impurities)
Porphyritic Basalt (Chinese Flower Stone / Chrysanthemum Stone basalt variety)
Porphyritic Basalt containing Plagioclase Feldspar phenocrysts
Basalt (tumbled/river-worn)
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Olivine in Basalt
Peridotite / Forsterite ((Mg,Fe)2SiO4)
Apache Tear
Obsidian (Hydrated Volcanic Glass - SiO2)
Apache Tear (Obsidian)
Volcanic glass / Amorphous SiO2
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)
Snowflake Obsidian
Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)
Pegmatite
Pegmatitic Granite
Granatic Pegmatite
Pegmatitic Granite
Pumice
Vesicular Rhyolite or Dacite
Basalt Pebble
Basalt (Mafic volcanic rock)
Pegmatitic Granite
Granite (Alkali-feldspar granite) with Quartz and Orthoclase
Obsidian
Obsidian (Amorphous volcanic glass, predominantly SiO2)
Granite Cobble
Granite (Phaneritic Quartz-Feldspar-Mica intrusive rock)
Basalt (Vesicular)
Basalt (mostly plagioclase, pyroxene, and olivine)
Granodiorite (foreground) and Rose Quartz (background)
Granodiorite / Quartz (SiO2)
Andesite
Andesite (Intermediate Volcanic Rock)
Scoria (Lava Rock)
Scoria
Basalt with vesicles/amygdules
Basalt (containing volcanic glass and plagioclase)
Pumice
Pumice (a highly vesicular volcanic glass)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Basalt (River Stone)
Basalt
Diorite (Salt and Pepper Rock)
Diorite
Porphyritic Basalt
Porphyritic Mafic Extrusive Rock
Granite
Granite (Alkali feldspar, Plagioclase feldspar, and Quartz)
Granite Pebble
Granite (composition of Quartz, Alkali Feldspar, and Plagioclase)
Pumice
Pumice (Vesicular volcanic glass)
Granite
Granite (Felsic Plutonic Rock)
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Pumice
Pumice (a highly vesicular volcanic glass)
Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
Basalt River Stone
Basalt (Mafic volcanic rock)
Vesicular Basalt (River Rock)
Afanitic Vesicular Basalt
Pumice
Pumice (a highly vesicular volcanic rock)
Basalt (River Rock/Cobble)
Basalt (no specific mineral formula as it's a rock)
Granite
Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase)
Basalt
Basalt (composition of plagioclase feldspar and pyroxene)
Porphyritic Basalt
Amygdaloidal Porphyritic Basalt