Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Igneous
Category
Metamorphic Rock (Primarily Composed Of Minerals)
Browse metamorphic rock (primarily composed of minerals) specimens identified by the Rock Identifier community.
Diabase (Greenstone)
Diabase (also known as Dolerite)
igneous
Banded Agate Geode
Silicon Dioxide (SiO2)
mineral
Diorite
Diorite (Intermediate plutonic rock)
igneous
Turquoise
Hydrous phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
metamorphic
Granite
Phaneritic high-silica plutonic rock (composed primarily of Quartz, Feldspar, and Mica)
igneous
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
Metamorphic
Conglomerate
Conglomerate (SiO2 matrix with various silicate clasts)
sedimentary
Ferruginous Sandstone
Clastic sedimentary rock (primarily Quartz with Iron Oxide cement)
sedimentary
Schist
Mica Schist
metamorphic
Pink Quartzite
Quartzite (SiO2 with minor iron oxide impurities)
metamorphic
Dalmatian Jasper (Dalmatian Stone)
Perthitic feldspar with Arfvedsonite inclusions
igneous
Sapphire (Raw/Rough)
Corundum (Al2O3)
mineral
Red Sandstone
Arenite (with Iron Oxide cement)
sedimentary
Ruby in Fuchsite (often confused with Ruby in Zoisite)
Corundum (Al2O3) in Chromium-rich Muscovite (KAl2(AlSi3O10)(OH)2)
metamorphic
Prehnite
Calcium aluminum silicate hydroxide - Ca2Al(AlSi3O10)(OH)2
mineral
Schist
Mica Schist (Variable chemistry, often rich in muscovite and biotite)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Quartzite
Quartzite (primarily SiO2)
metamorphic
Granite
Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Ironstone Concretion (Moqui Marble Type)
Goethite/Hematite-cemented Sandstone Concretion
sedimentary
Quartz Geode
Silicon Dioxide (SiO2) in Geode form
sedimentary
Demantoid Garnet on Matrix
Demantoid (variety of Andradite Garnet) - Ca3(Fe3+)2(SiO4)3
mineral
Stichtite in Serpentine (Atlantisite)
Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)
Metamorphic
Coal (most likely Bituminous or Anthracite)
Coal (primarily composed of carbon with varying amounts of other elements)
Sedimentary rock
Charoite
Charoite (Hydrated potassium sodium calcium barium strontium silicate hydroxyfluoride)
metamorphic
Diorite
Phaneritic plutonic rock (dominated by plagioclase feldspar and hornblende)
igneous
Green Opal
Hydrated Silica (SiO2·nH2O)
mineraloid
Conglomerate (River Rock)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Turquoise
Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
mineral
Quartzite (River Pebble)
Metamorphic rock consisting primarily of Quartz (SiO2)
metamorphic
Pyrite on Quartz
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
mineral
Blue Calcite
Calcium Carbonate (CaCO3)
mineral
Chrome Diopside
Magnesium Calcium Silicate (MgCaSi2O6) containing Chromium impurities
mineral
Red Quartzite Slipper Stone
Quartzite (SiO2)
metamorphic
Amygdaloidal Basalt
Vesicular Basalt with secondary mineral infilling (commonly Zeolite, Calcite, or Quartz)
igneous
Pink Granite (Potassium-rich Granite)
Phaneritic Felsic Igneous Rock (primarily SiO2, Al2O3, K2O)
Igneous
Blue Quartzite (Aventurine variety)
Silicon Dioxide (SiO2) with inclusions of Dumortierite or Magnesio-riebeckite
metamorphic