Ironstone Concretion (likely)
Goethite/Hematite/Limonite cemented sediment
Category
Browse sedimentary rock (technically a microcrystalline quartz mineral aggregate) specimens identified by the Rock Identifier community.
Ironstone Concretion (likely)
Goethite/Hematite/Limonite cemented sediment
Quartzite
Quartzite (SiO2)
Jasper Breccia
Brecciated Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
Granite
Phaneritic Granocrystalline Igneous Rock
Granite with Orthoclase and Hematite Staining
Phaneritic Felsic Igneous Rock (primarily SiO2 with KAlSi3O8)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Sandstone (Yellow/Tan Sandstone)
Arenite (primarily Quartz, SiO2)
Granite
Phaneritic Igneous Rock (Granite)
Clear Quartz
Silicon Dioxide (SiO2)
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
Granite (Pegmatitic)
Phaneritic Felsic Igneous Rock
Weathered Sandstone with Algae Growth
Arenite
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone (Calcareous or Ferruginous)
Clastic sedimentary rock (SiO2 with CaCO3 or Fe2O3 cement)
Quartz (Milky/Clear variety)
Silicon Dioxide (SiO2)
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in Geode form
Chalcedony (Grey/White Agate)
Silicon Dioxide (SiO₂)
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Chert (Common Opal/Agate inclusion)
Microcrystalline Quartz (SiO2)
Pyrite in Matrix (Quartz/Schist)
Iron Sulfide (FeS2)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive volcanic rock)
Sandstone (Fossiliferous)
Arenite / Clastic Sedimentary Rock
Granite
Granite (Phaneritic Quartz-Feldspar Rock)
Yellow Quartzite Pebble
Quartzite (primarily Silicon Dioxide - SiO2)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic volcanic rock)
Carnelian (Orange Agate)
Silicon Dioxide (SiO2)
Carnelian Agate (with Quartz/Chalcedony)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Sandstone
Arenite (primarily Quartz, SiO2)
Sandstone
Arenite (primarily SiO2)
Banded Agate (specifically Moss or River Agate variety)
Cryptocrystalline Quartz (SiO2)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Gneiss with Quartz Vein
Gneiss containing Quartz (SiO2) filler
Quartz in Matrix (possibly with Biotite or Hornblende)
Quartz (Silicon Dioxide, SiO2) in Granitic Matrix
Granite (Weathered)
Phaneritic Felsic Igneous Rock
Milky Quartz
Silicon Dioxide (SiO2)
Banded Agate (specifically Sardonyx)
Silicon Dioxide (SiO2) - variety of Chalcedony/Quartz
Gneiss (Banded Gneiss)
Gneiss
Chrysoprase
Chalcedony (cryptocrystalline SiO2 variety)
Amygdaloidal Basalt
Vesicular-Amygdaloidal Basalt (Mafic Extrusive)
Chert (specifically Flint Arrowhead)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Pyrite in Quartz
Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)
Green Quartzite
Quartzite (SiO2)