Granite
Granite (compositionally of Quartz, Alkali Feldspar, and Plagioclase)
Category
Browse igneous rock (volcanic glass) specimens identified by the Rock Identifier community.
Granite
Granite (compositionally of Quartz, Alkali Feldspar, and Plagioclase)
Granite
Granite (Phaneritic Quartz-Feldspar Igneous Rock)
Quartzite
Quartzite (SiO2)
Quartz
Quartz (SiO₂)
Granite
Granite (Mainly Quartz, Alkali Feldspar, and Plagioclase)
Blue Lace Agate
Cryptocrystalline Quartz (SiO2) with trace minerals
Quartzite
Quartzite (primarily SiO2)
Red Quartzite (Ferruginous Quartz)
Quartzite (SiO2 with Fe2O3 inclusions)
Dalmatian Stone (commonly called Dalmatian Jasper)
Peralkaline Rock (mixed Feldspar, Quartz, and Arfvedsonite)
Dyed Agate
Silicon Dioxide (SiO2)
Granodiorite
Granodiorite (Intermediate to Felsic Intrusive Rock)
Quartzite with Iron Inclusions
Metamorphic Quartzite (SiO2 with Fe2O3 trace impurities)
Gneiss
Gneissic Metamorphic Rock
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
Quartz Geode (partially formed)
Silicon Dioxide (SiO2)
Dalmatian Stone
Dalmatian Stone (a peralkaline igneous rock consisting of Feldspar, Quartz, and Arfvedsonite)
Quartz with Muscovite Mica
SiO2 with KAl2(AlSi3O10)(OH)2
Banded Agate (specifically Sardonyx Agate)
Silicon Dioxide (SiO2) - Chalcedony variety
Agate (Polished Nodule)
Agate (Silicon Dioxide, SiO2)
Carnelian
Carnelian (Chalcedony / SiO2)
Cinnabar in Quartz
Silicon Dioxide (Quartz, SiO2) with Mercury Sulfide inclusions (Cinnabar, HgS)
Quartz Geode
Silicon Dioxide (SiO2)
Jasper
Cryptocrystalline Quartz (SiO2)
Black Opal
Hydrated silica (SiO2·nH2O)
African Turquoise
African Turquoise (a trade name for Jasper, a variety of Chalcedony: SiO2)
White Chalcedony (likely Common Opal or Milky Quartz)
Silicon Dioxide (SiO2)
Pink Botswana Agate
Silicon Dioxide (SiO₂), a cryptocrystalline variety of Quartz and Chalcedony
Moss Agate
Silicon Dioxide with inclusions (SiO2 + Fe/Mn/Mg)
Larimar
Blue Pectolite (NaCa2Si3O8(OH))
Banded Rock (likely Quartz-rich)
Uncertain, likely a Metamorphic Rock (e.g., Gneiss or Schist) with prominent Quartz and other minerals
Green glass sphere/marble
Soda-lime glass (primarily SiO2, Na2O, CaO)
Quartz Geode
Silicon Dioxide (SiO2) in Geode form
Greywacke (likely)
Greywacke (a type of sandstone)
Granodiorite
Granodiorite (Phaneritic intrusive igneous rock containing Plagioclase, Quartz, and Biotite/Amphibole)
Milky Quartz
Silicon Dioxide (SiO2)
Chalcedony in Limestone Host Rock
Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)
Quartz
Silicon Dioxide (SiO2)
Red Slag Glass
Amorphous Silica (Industrial byproduct with metallic oxide dopants)
River Stone (Granitic Gneiss)
Foliated Granitic Gneiss
Jasper
Jasper (Cryptocrystalline Quartz; SiO2)
Nuummite
Nuummite (intergrowth of orthoamphiboles Anthophyllite and Gedrite, (Mg,Fe)7Si8O22(OH)2)