Granite
Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase Feldspar)
Category
Browse sedimentary or igneous fragment specimens identified by the Rock Identifier community.
Granite
Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase Feldspar)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz Crystal Cluster
Quartz (Silicon Dioxide, SiO2)
Ruby
Corundum (Al2O3:Cr)
Quartz Vein in Host Rock
Quartz (SiO2) in Mafic or Sedimentary Matrix
Pink Granite
Phaneritic Plutonic Felsic Igneous Rock (Granite)
Granite Cobble
Phaneritic Felsic Igneous Rock (Granite)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Tourmaline (likely Schorl)
Tourmaline Group Mineral (e.g., Schorl for black varieties); (Na,Ca)(Li,Mg,Fe,Mn,Al)3Al6(BO3)3Si6O18(OH)4
Quartz Pebble
Silicon Dioxide (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Green Fluorite
Calcium Fluoride (CaF2)
White Quartz (Milky Quartz)
Quartz (Silicon Dioxide, SiO2)
Gneiss
High-grade Metamorphic Gneiss
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Gneiss
High-grade foliated metamorphic rock
Mixed collection of minerals and rocks (Jasper, Carnelian, Granite, and Quartz)
Silicon Dioxide (SiO2) with varying impurities for silicates and igneous aggregates
Precious Opal
Hydrated Silica (SiO2·nH2O)
Leopard Skin Jasper
Silicon Dioxide (SiO2) with impurities
Sodalite (blue beads) and Clear Quartz (clear beads)
Sodalite: Na4Al3Si3O12Cl; Quartz: SiO2
Wonderstone (Banded Rhyolite)
Rhyolite (Silicon Dioxide with Iron Oxide impurities)
Greenstone / Diabase Porphyry
Porphyritic Diabase (Micro-gabbro)
Pyrite
Pyrite (FeS2)
Sandstone
Sandstone (arenite is a more specific geological term for a clean sandstone, while wacke refers to a dirty sandstone with significant matrix)
Quartz
Quartz (SiO₂)
Quartz
Quartz (Silicon Dioxide, SiO2)
Chalcedony (Agate/Jasper mix in host rock)
Chalcedony (cryptocrystalline Silicon Dioxide, SiO2)
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Gneiss (Metamorphic Rock)
Gneiss
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Gneiss Pebble
Gneiss
Milky Quartz
Silicon Dioxide (SiO2)
Gneiss (specifically a Granitic Gneiss)
Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)
Quartz (Milky/Gravel variety)
Silicon Dioxide (SiO2)
Almandine Garnet
Almandine (Fe3Al2(SiO4)3)
Veined Quartz
SiO2 (Silicon Dioxide)
Amethyst Quartz
SiO2 (Silicon Dioxide)
Basalt with Caliche Crust
Aphanitic Mafic Igneous Rock with Calcium Carbonate (CaCO3) coating
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 inclusions)
Diabase (also known as Dolerite)
Diabase / Dolerite