Apache Tear
Hydrated Obsidian (Volcanic Glass)
Category
Browse sedimentary and igneous (mixed) specimens identified by the Rock Identifier community.
Apache Tear
Hydrated Obsidian (Volcanic Glass)
Granite Cobble
Granitoid (typically containing Quartz SiO2, Feldspar KAlSi3O8, and Mica minerals)
Tektite (Indochinite)
Tektite (Amorphous Silica Glass)
Obsidian
Obsidian (Amorphous volcanic glass)
Granite (Core Sample)
Phaneritic Felsic Igneous Rock (Granite)
Granite Cobble
Phaneritic Felsic Igneous Rock
Olivine in Basalt (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4 in Vesicular Basalt
Spinifex Textured Komatiite
Komatiite (Mg-rich ultramafic volcanic rock)
Greenstone (Amygdaloidal Basalt)
Amygdaloidal Basalt (frequently composed of Plagioclase Feldspar, Pyroxene, and Olivine with Chlorite inclusions)
Pumice
Vesicular volcanic glass (primarily SiO2 with Al2O3)
Granitic Pegmatite
Coarse-grained Granite (KAlSi3O8 + SiO2)
Basalt (Greenstone)
Amygdaloidal Basalt / Chloritized Basalt
Diorite (Salt and Pepper Rock)
Phaneritic Plutonic Diorite; chemical composition roughly 52-63% silica (SiO2)
Pink Granite (Potassium-rich)
Phaneritic Felsic Igneous Rock (K-Feldspar Granite)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive volcanic rock)
Peridotite (with Olivine and Pyroxene)
Ultramafic Magmatic Rock (Primary minerals: (Mg, Fe)2SiO4 and (Ca, Mg, Fe)2Si2O6)
Andesite Porphyry
Andesite (extrusive volcanic rock)
Obsidian
Obsidian (principally SiO2)
Granite
Phaneritic Felsic Igneous Rock
Pumice
Pumice (Vesicular felsic extrusive igneous rock)
Quartz in Host Rock
Silicon Dioxide (SiO2) in Rhyolite or Granite matrix
Obsidian
Obsidian (Volcanic Glass)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)
Porphyritic Basalt (Peanut Obsidian/Star Galaxy-style)
Porphyritic Basalt (Silica-rich Volcanic Rock)
Pegmatite (with Quartz and Feldspar)
Granitic Pegmatite
Granite (Specimen: Logan Rock)
Phaneritic plutonic igneous rock (mainly Quartz, Feldspar, and Mica)
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Obsidian
Obsidian (principally SiO2 - Silicon Dioxide)
Pink Granite
Granite (Phaneritic Quartz-Feldspar rock)
Rough Quartz in Pegmatite Matrix
Quartz (Silicon Dioxide - SiO2) in Granitic Pegmatite
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Porphyry
Porphyritic Rhyolite or Andesite
Red Porphyry
Porphyritic Andesite or Rhyolite
Obsidian
Volcanic glass (SiO2 - Silicon dioxide predominant composition)
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Alkali Feldspar, and Plagioclase)
Pumice
Pumice (Vesicular volcanic glass)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Sodalite Syenite
Sodalite-bearing Syenite (Na8(Al6Si6O24)Cl2)
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions
Chinese Writing Stone
Porphyritic Basalt or Porphyritic Andesite with Feldspar phenocrysts (SiO2-rich Silicates)
Porphyritic Basalt (with Amygdales)
Amygdaloidal Porphyritic Basalt