Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
Category
Browse igneous (anthropogenic) specimens identified by the Rock Identifier community.
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
Basalt
Mafic volcanic rock (consisting mostly of plagioclase, pyroxene, and olivine)
Basalt with Epidote (Flowerstone-like texture)
Amygdaloidal Basalt (silicate mineral inclusions)
Granitic Quartz with Feldspar
Granite (composed primarily of SiO2 and KAlSi3O8)
Basalt with Amygdaloidal Inclusions
Aphanitic Mafic Volcanic Rock (Basalt)
Basalt (Weathered)
Extrusive mafic volcanic rock
Basalt Pebble
Basalt (Aphanitic Mafic Volcanic Rock)
Basalt
Basalt (primarily Plagioclase feldspar and Pyroxene)
Basalt (Crushed Stone Aggregate)
Mafic Volcanic Basalt (Major Minerals: Plagioclase Feldspar, Pyroxene, Olivine)
Granite (Weathered)
Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica)
Vesicular Basalt
Mafic Volcanic Rock (Basalt)
Obsidian
Volcanic Glass (70-75% SiO2)
Obsidian
Obsidian (principally SiO2)
Porphyritic Basalt
Porphyritic Basalt (containing Plagioclase or Alkali Feldspar phenocrysts)
Diorite
Phaneritic Intermediate Plutonic Rock
Ocean Jasper (Orbicular Jasper)
Spherulitic Chalcedony (SiO2)
Obsidian
Volcanic Glass (Silicon Dioxide with impurities)
Basalt
Basalt (dominated by Plagioclase Feldspar and Pyroxene)
Snowflake Obsidian
Spherulitic Obsidian (SiO2 + impurities)
Rhyolite
Rhyolite (High-silica volcanic rock)
Granite
Granite (composition: Quartz, Feldspar, Mica)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
Amygdaloidal Basalt
Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)
Basalt
Afanitic Mafic Basalt
Pumice
Highly vesicular volcanic glass (unnamed scientific variant: Rhyolitic/Andesitic Pumice)
Olivine Peridotite
Peridotite (comprising Olivine (Mg,Fe)2SiO4 and Pyroxene)
Pumice
Pumice (Vesicular volcanic glass)
Diorite (Gneissic)
Diorite
Orbicular Granite (specifically Mustard or Yellow Tonalite/Granodiorite)
Orbicular Quartz Diorite / Tonalite
Basalt with Calcite Veins
Aphanitic mafic volcanic rock with CaCO3 inclusions
Lunar Meteorite (Feldspathic Breccia)
Lunar Achondrite (Regolith Breccia)
Olivine (Peridotite)
(Mg,Fe)2SiO4 (Magnesium Iron Silicate)
Pegmatite (Granitic)
Granitic Pegmatite containing Quartz, Feldspar, and Tourmaline (Schorl)
Black Obsidian
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions (SiO2 + Fe2O3)
Dyed Pumice
Vesicular Rhyolite (Artificial Coloration Addition)
Obsidian
Volcanic glass (mainly SiO2 with inclusions)
Diorite (Salt and Pepper Rock)
Diorite
Mahogany Obsidian
Obsidian (Volcanic Glass) with Hematite/Magnetite inclusions
Basalt with Phenocrysts (Porphyritic Basalt)
Porphyritic Basalt (primarily Plagioclase and Pyroxene)
Obsidian
Volcanic Glass (predominantly SiO2)