Sandstone (Ferruginous)
Arenite with Iron Oxide (Limonite/Hematite) coating
Category
Browse sedimentary rock (cryptocrystalline quartz) specimens identified by the Rock Identifier community.
Sandstone (Ferruginous)
Arenite with Iron Oxide (Limonite/Hematite) coating
Gneiss
Gneiss (Metamorphic rock composed primarily of quartz, feldspar, and mica)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Chrysocolla on Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O
Turquoise
Hydrated phosphate of copper and aluminum; CuAl6(PO4)4(OH)8·4H2O
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with iron oxide impurities
White Quartz Pebble (Milky Quartz)
Silicon Dioxide (SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide - SiO2)
Blue Quartzite
Quartzite (primarily SiO2) with inclusions like Dumortierite or Magnesio-riebeckite
Thunderegg
Agate-filled Rhyolitic Nodule (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Ocean Jasper
Spherulitic Chalcedony (SiO2)
Yellow Quartz
SiO2 (Silicon Dioxide)
Vesicular Basalt with Quartz/Chalcedony
Vesicular Basalt (primarily Plagioclase, Pyroxene, and Olivine with SiO2 infill)
Chert (Flint)
Chert (SiO2)
Granite
Granite
Agate (or Banded Agate)
Agate (a variety of Chalcedony, which is a cryptocrystalline form of Quartz); Chemical Formula: SiO₂ (Silicon Dioxide)
Moss Agate
Silicon dioxide (SiO2) with inclusions of hornblende or chlorite
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (SiO2)
Quartzite Cobble
Quartzite (primarily SiO2)
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Granite fragment
Granite
Slate
Foliated Metamorphic Rock (primarily composed of quartz, illite, and chlorite)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Metasedimentary or Igneous Matrix
Unakite
Epidotized Granite
Tiger's Eye (Mineral Collection)
Tiger's Eye (SiO2 with crocidolite inclusions)
Turquoise in Matrix
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Milk Quartz (with Iron staining)
Silicon Dioxide (SiO2)
Botryoidal Chalcedony
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with Iron impurities
Quartz / Quartzite
Silicon Dioxide (SiO2)
Granite
Phaneritic Felsic Igneous Rock
Chert (often called Flint when dark or worked)
Cryptocrystalline silica (SiO2)
Dalmation Jasper (Dalmation Stone)
Perthitic feldspar-quartz-amphibole rock
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Milky Quartz / Rose Quartz fragment
Silicon Dioxide (SiO2)
Sandstone (lithic wacke)
Arenite / Lithic Wacke (mostly SiO2 with rock fragments)
African Turquoise
Teal Jasper (Macro-crystalline Quartz/Sio2 + Inclusions of Copper, Iron, and Manganese)