Snowflake Obsidian
Volcanic glass containing Spherulitic inclusions (SiO2 + impurities)
igneous
Category
Igneous
Browse igneous specimens identified by the Rock Identifier community.
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Basalt
Basalt (Volcanic Mafic Rock)
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt with Quartz Veining
Veined Basalt (composed primarily of plagioclase feldspar, pyroxene, and olivine with quartz/calcite infill)
igneous
Basalt
Basalt
igneous
Snowflake Obsidian
Hydrated Volcanic Glass with Cristobalite inclusions
igneous
Obsidian
Volcanic Glass (SiO2)
igneous
Obsidian with Slate/Tuff
Volcanic glass (SiO2) with associated pyroclastic rock
igneous
Obsidian
Obsidian
Igneous
Granite
Phaneritic Plutonic Rock (primarily SiO2, Al2O3, K2O, Na2O)
igneous
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
igneous
Granite
Granite (composed primarily of Quartz SiO2, Potassium Feldspar KAlSi3O8, and Plagioclase)
igneous
Obsidian
Obsidian (Volcanic Glass)
igneous
Pumice
Pumice (a frothy volcanic glass)
igneous
Obsidian
Volcanic Glass (SiO2)
igneous
Obsidian
Obsidian (volcanic glass), primarily SiO2 (silicon dioxide)
igneous
Vesicular Basalt (commonly mistaken for Slag)
Scoriaceous Basalt (composed primarily of Plagioclase Feldspar and Pyroxene)
igneous
Granite
Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar (K,Na)AlSi3O8, and Plagioclase Feldspar)
igneous
Obsidian
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Igneous
Red Scoria
Scoria (Vesicular Basalt/Andesite)
igneous
Quartz Vein Rock
Quartz (Silicon Dioxide, SiO2)
igneous
Basalt with Peridotite (Olivine) Xenolith
Olivine-rich Peridotite (Dunite) xenolith in Vesicular Basalt; chemical formula (Mg,Fe)2SiO4
igneous
Granite (including Pegmatite variants)
Phaneritic Plutonic Rock (composed primarily of Quartz SiO2, Feldspar KAlSi3O8, and Biotite/Muscovite mica)
Igneous
Greenstone (Amygdaloidal Basalt)
Amygdaloidal Basalt (frequently composed of Plagioclase Feldspar, Pyroxene, and Olivine with Chlorite inclusions)
igneous
Golden Sheen Obsidian
Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen
igneous
Diamond in Kimberlite
Diamond in Kimberlite Matrix (Diamond: C, Kimberlite: complex Potassic Peridotite)
igneous
Granite (Alkali-feldspar Granite)
Felsic Plutonic Rock (Primary minerals: Quartz SiO2, Orthoclase KAlSi3O8, Plagioclase (Na,Ca)AlSi3O8)
igneous
Obsidian (likely Golden Sheen Obsidian or Rainbow Obsidian, given the subtle sheen visible on some beads)
Obsidian (volcanic glass, predominantly SiO2 with various impurities)
Igneous
Vesicular Basalt
Extrusive mafic igneous rock; primarily (Ca,Na)(Mg,Fe,Al,Si)2O6 (Pyroxene) and (Ca,Na)Al(Al,Si)Si2O8 (Plagioclase Feldspar)
igneous
Amygdaloidal Basalt with Agate/Chalcedony Infills
Amygdaloidal Basalt (Composition: SiO2 and (Mg,Fe)2SiO4 in matrix; SiO2 in amygdule)
igneous
Pumice
Pumice (volcanic glass)
igneous
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
igneous
Pumice
Pumice (a volcanic glass, primarily SiO2 with Al2O3)
igneous
Black Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
igneous
Basalt
Extrusive mafic rock
igneous
Basalt with Feldspar phenocrysts
Aphanitic to Porphyritic Mafic Volcanic Rock
igneous
Porphyry (specifically Porphyritic Basalt or Andesite)
Porphyritic extrusive igneous rock (Mg,Fe)2SiO4 (Olivine inclusions/Plagioclase Feldspar)
igneous
Scoria
Highly vesicular mafic volcanic rock
igneous
Pink Granite
Phaneritic Quartz-Feldspar Plutonic Rock
igneous
Basalt
Basalt (primarily composed of Plagioclase feldspar and Pyroxene)
igneous
Granite
Phaneritic Plutonic Felsic Rock (SiO2 > 63%)
igneous
Basalt with Quartz Infill
Basalt (Mafic Extrusive Volcanic Rock)
igneous