Golden Sheen Obsidian
Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen
igneous
Category
Igneous
Browse igneous specimens identified by the Rock Identifier community.
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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
Pumice
Pumice (volcanic glass foam)
igneous
Pumice
Pumice (Amorphous volcanic glass)
igneous
Snowflake Obsidian
Spherulitic Obsidian (primarily SiO2)
igneous
Diorite
Diorite (Intermediate Plutonic Rock)
igneous
Granite
Granite (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Vesicular Basalt with Epidote/Amygdaloidal Basalt
Amygdaloidal Basalt (Mg, Fe)2SiO4 + Ca2(Al, Fe)3(SiO4)3(OH)
igneous
Scoria
Vesicular Basalt / Scoria
igneous
Vesicular Basalt (Amygdaloidal)
Amygdaloidal Basalt (Mafic volcanic rock)
igneous
Granite River Pebble
Granite
igneous
Granite
Phaneritic Plutonic Felsic Rock
igneous
Diorite (Salt and Pepper Rock)
Diorite
igneous
Basalt (Vesicular)
Vesicular Basalt
Igneous
Basalt
Basalt
igneous
Labradorite (a variety of Anorthosite or Plagioclase)
Labradorite (member of Plagioclase Feldspar series), (Ca,Na)(Al,Si)4O8
igneous
Diorite (Pebble)
Diorite
igneous
Diorite
Diorite (Intermediate Plutonic Rock)
igneous
Obsidian
Volcanic glass (mainly SiO2)
Igneous
Vesicular Basalt with Pyrite
Basalt (MgFe2+)(Si,Al)2O6 containing FeS2 inclusions
igneous
Basalt Cobble
Vesicular Basalt (Mafic Extrusive)
igneous
Basalt with Quartz/Calcite Veins
Amygdaloidal Basalt (SiO2 or CaCO3 inclusions)
igneous
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Pumice
Pumice (volcanic glass with vesicular texture)
igneous
Granite
Granite (phaneritic intrusive igneous rock consisting of 20-60% quartz, orthoclase/plagioclase feldspar, and mica/amphibole)
igneous
Pumice
Pumice (Vesicular Rhyolite)
igneous