Amazonite
Microcline (KAlSi3O8) with lead impurities
Category
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Amazonite
Microcline (KAlSi3O8) with lead impurities
Banded Chert
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Larimar (with dendritic inclusions)
Blue Pectolite (NaCa2Si3O8(OH))
Blue Apatite
Fluoroapatite (Ca5(PO4)3F)
Native Gold
Gold (Au)
White Howlite
Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Agate
Silicon dioxide (SiO2)
Red Garnet
Garnet Group (e.g., Pyrope, Almandine, Spessartine, Grossular, Andradite, Uvarovite)
Lunar Meteorite (Feldspathic Breccia)
Lunar Achondrite (Regolith Breccia)
Quartzite
Quartzite (primarily SiO2)
Sandstone Beach Pebble
Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)
Quartzite
Quartzite (SiO2)
Quartz Vein in Metamorphic Rock
Silicon Dioxide (SiO2) within Metasedimentary host
Unakite (Tumbled)
Unakite (altered granite)
Quartzite Pebble (Beach Pebble)
Quartzite (primarily SiO2)
Quartzite
Metamorphic Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Pyrite in Quartz
FeS2 (Iron Pyrite) with SiO2 (Quartz)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Sandstone (with Arkose characteristics)
Clastic sedimentary rock (SiO2 with KAlSi3O8)
Lepidolite
K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2
Hypersthene
Hypersthene (Enstatite variety), (Mg,Fe)SiO3
Chert
Silicon dioxide (SiO2)
Slag (Industrial)
N/A (Anthropogenic Slag)
Quartzite
Quartzite (primarily Silicon Dioxide, SiO2)
Amethyst
Amethyst (Silicon Dioxide, SiO2)
Quartzite
Quartzite
Quartzite River Rock
Quartzite (primarily SiO2)
Dumortierite Quartz
Dumortierite (Al7BCuO15)
Oceanside Agate (Orbicular Agate)
Silicon Dioxide (SiO2) - Variety of Chalcedony
Quartzite
Quartzite (SiO2)
Limestone Cobble
Sedimentary Calcium Carbonate (CaCO3)
Greenstone
Greenschist / Meta-basalt
Chert nodules
Microcrystalline Quartz (SiO2)
Jasper
Silicon dioxide (SiO2)
Orange Quartzite
Quartzite (primarily SiO2 with hematite or iron oxide inclusions)
Iron-stained Quartz
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3/FeO(OH))
Quartz Druze on Matrix
Silicon Dioxide (SiO2)
Siltstone
Siltstone (primarily SiO2 with Al2O3)