Agate (specifically, a slice of a Blue Lace or Chalcedony Agate nodule)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Category
Browse sedimentary (secondary classification: cryptocrystalline quartz) specimens identified by the Rock Identifier community.
Agate (specifically, a slice of a Blue Lace or Chalcedony Agate nodule)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Ammonite Fossil
Ammonoidea
Chert (Flint) with Iron Staining
Microcrystalline Quartz (SiO2)
Carnelian
Chalcedony (cryptocrystalline quartz), SiO2
Chert / Flint (with quartz or calcite inclusion)
Silicon dioxide (SiO2)
Chert Pebble with Quartz Veining
Microcrystalline Quartz (SiO2)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Chert (Flint)
Microcrystalline Quartz (SiO2)
Porphyritic granite boulder
Granite, commonly quartz–alkali feldspar–plagioclase with biotite/hornblende
Chert (specifically Agate/Jasper variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Weathered granite pebble
Granite; primarily quartz, feldspar, and mica
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O
Chert (with Manganese Oxide coating)
Microcrystalline Quartz (SiO2)
Jasper (Zebra Jasper)
Silicon Dioxide (SiO2) with impurities
Jasper and Quartzite Pebble
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Rounded river cobble, likely weathered sandstone or quartz-rich metasandstone
Indeterminate sandstone; commonly quartz (SiO₂) with feldspar, lithic grains, and iron-oxide cement
Milky quartz-rich rock, likely quartzite or quartz vein material
Quartz (SiO₂), probably intergrown with feldspar and weathered mica/clay minerals
Dalmatian jasper (likely orbicular microgranite)
Quartz–feldspar–biotite/pyroxene microgranite; commonly marketed as Dalmatian jasper
Agate
Cryptocrystalline Quartz (SiO2)
Carnelian Agate
Silicon Dioxide (SiO2) - variety of Chalcedony
Chalcedony (Botryoidal)
Silicon Dioxide (SiO2)
Chrysocolla
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O
Brecciated Chert
Brecciated Chert (Microcrystalline Quartz, SiO2)
Polished pink granite cobble
Granite, chiefly potassium feldspar, plagioclase, quartz, and biotite/hornblende
Agate Geode
Silicon Dioxide (SiO2) - variety Chalcedony/Quartz
Agate
Silicon Dioxide (SiO2)
Agate (specifically Lace Agate or Banded Agate)
Silicon Dioxide (SiO2)
Red Jasper with Quartz Vein
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Chert (specifically a variety like Flint or River Jasper with Iron Oxidation)
Microcrystalline Quartz (SiO2)
Agate
Cryptocrystalline Quartz (SiO2)
Chert (with Quartz Vein)
Chert (Siliceous sedimentary rock, predominantly Microcrystalline Quartz SiO2)
Chert (with Limestone/Carbonate matrix)
Sedimentary cryptocrystalline silica (SiO2)
Raw Agate (Chalcedony Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Lunar Meteorite
Lunar Feldspathic Breccia
Chrysocolla in Quartz
Hydrated copper phyllosilicate with silicon dioxide (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O + SiO2)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Chert (Limestone-based)
Silicon Dioxide (SiO2)
Jasper (Green Jasper / Chert)
Silicon Dioxide (SiO2 with inclusions)
Black Onyx
Chalcedony (SiO2)
Chert (Jasper / Flint variant)
Microcrystalline Quartz (SiO2)
Banded Agate / Chalcedony
Cryptocrystalline Quartz (SiO2)
Weathered quartz-rich rock, possibly granite or quartzite
Indeterminate; likely quartz (SiO₂) with feldspar and minor mica, or quartzite