Porphyritic Basalt
Porphyritic Basalt (containing Plagioclase phenocrysts)
igneous
Category
Mineral Based Composite
Browse mineral based composite specimens identified by the Rock Identifier community.
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Diorite (Salt and Pepper Rock)
Diorite
igneous
Basalt
Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
igneous
Conglomerate
Conglomerate (Clastic sedimentary rock)
sedimentary
Gabbro (Water-worn Pebble)
Gabbro
igneous
Granite
Granite (composed of quartz, potassium feldspar, plagioclase, and mica/biotite)
igneous
Granite
Granite (Phaneritic Quartz-Feldspar Plutonic Rock)
igneous
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
igneous
Schist (Micaceous Schist)
Schist (comprising Muscovite/Biotite mica, Quartz, and Feldspar)
metamorphic
Sandstone (Micaceous Sandstone)
Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)
sedimentary
Mica Schist
Mica Schist (Quartz-Biotite-Muscovite Schist)
metamorphic
Granite (Pink/Potassium Feldspar rich)
Granite (K-feldspar rich intrusive igneous rock)
igneous
Basalt with Magnetite inclusions
Basalt (Mafic silicate rock) potentially containing Magnetite (Fe3O4)
igneous
Quartz (Water-worn Pebbles)
Silicon Dioxide (SiO2)
mineral
Basalt with Scoria/Vesicular Texture
Vesicular Basalt (Iron-rich/Oxidized)
igneous
Garnet in Schist
Almandine Garnet in Mica-Schist (Fe3Al2(SiO4)3)
metamorphic
Sandstone (Iron-stained)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
sedimentary
Basalt with Quartz Vein
Basalt (SiO2 vein inclusion)
igneous
Aqua Aura Quartz
Titanium/Gold-coated Silicon Dioxide (SiO2)
mineral
Basalt with Quartz/Calcite Veins
Extrusive mafic igneous rock with hydrothermal mineralization
igneous
Basalt with Iron Oxidation
Mafic Igneous Rock (Basalt)
igneous
Bloodstone / Heliotrope
Cryptocrystalline Quartz (SiO2 with inclusions)
sedimentary
African Turquoise (Jasper)
Impure variety of silica, primarily Quartz (SiO2) with various inclusions
sedimentary
Amygdaloidal Basalt
Amygdaloidal Basalt (Host rock) with Quartz or Calcite amygdules
igneous
Sandstone (Quartz-rich Pebble)
Arenite (primarily SiO2)
sedimentary
Mica Schist
Mica Schist (Predominantly Muscovite/Biotite)
metamorphic
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
igneous
Conglomerate
Conglomerate (clastic sedimentary rock)
sedimentary
Weathered volcanic rock, likely basalt
Basalt; commonly composed of plagioclase, pyroxene, and iron-rich oxides
igneous
Scoria (with Iron Oxidation)
Vesicular Basalt / Scoria
igneous
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
sedimentary
Spherulitic Rhyolite / Leopard Skin Rhyolite
Extrusive felsic igneous rock with spherulites
igneous
Mica-rich Sandstone or Micaceous Schist Weathering
Micaceous Schist (Muscovite-Quartz composition)
Metamorphic or Sedimentary depending on local grade
Schist
Mica Schist (Group of medium-grade metamorphic rocks)
metamorphic
Mica Schist
Mica Schist (Main mineral constituents: Muscovite/Biotite, Quartz, Feldspar)
metamorphic
Jasper with Quartz Veining
Silicon Dioxide (SiO2) with impurities
sedimentary
White Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
mineral
Mica Schist
Mica Schist (primarily Muscovite and Quartz)
metamorphic
Muscovite Schist
Muscovite (KAl2(AlSi3O10)(OH)2) in Schist
metamorphic
Basalt with Chert/Obsidian blade
Aphanitic Mafic Igneous Rock (Basalt) with Microcrystalline Silica (Chert)
igneous
Basalt with Plagioclase or Quartz Inclusion
Melanocratic Basalt with Porphyritic Inclusion
igneous