Quartz (Milky or Clear variety)
Silicon Dioxide (SiO2)
Category
Browse sedimentary rock (cryptocrystalline quartz) specimens identified by the Rock Identifier community.
Quartz (Milky or Clear variety)
Silicon Dioxide (SiO2)
Green Jasper
Silicon Dioxide (SiO2) with iron silicate inclusions
Vuggy Quartz on Matrix
Silicon Dioxide (SiO2)
Quartz (likely Chalcedony or Chert)
Silicon Dioxide (SiO2)
Sandstone (specifically Arkose or Ferruginous Sandstone)
Sandstone (SiO2 with iron oxide inclusions)
Petrified Wood
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Tumbled Carnelian and Quartz Mix
Silicon Dioxide (SiO2) with iron oxide impurities
Jasper (specifically Red or Brecciated Jasper variant)
Jasper (Microcrystalline Quartz - SiO2)
Quartz (likely Yellow/Orange variety, possibly Citrine or Chalcedony with iron staining)
Quartz (SiO₂)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Matrix
Jasper / Chert (River Pebble)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Quartz (likely Milky Quartz or Chalcedony)
Quartz (SiO2 - Silicon Dioxide)
Carnelian
Carnelian (a variety of Chalcedony, which is a microcrystalline quartz, SiO2)
Sandstone (likely Navajo Sandstone)
Arenite (primarily SiO2)
Granitic Gneiss
Gneiss (High-grade regional metamorphic rock)
Chert
Chert (Microcrystalline Quartz, SiO2)
Banded Chert / Banded Jasper (likely a variety of Chert/Chalcedony)
Chert (microcrystalline quartz)
Ferruginous Sandstone
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Sandstone (likely Quartzose Sandstone)
Arenite
Quartz Geode
Silicon Dioxide (SiO2) in a Secondary Sedimentary/Volcanic cavity
Druzy Quartz (on Quartzite or Chert)
Silicon Dioxide (SiO2)
Gneiss
Gneiss
Banded Carnelian
Carnelian (Silicon Dioxide / SiO2)
Jasper with Quartz (Agate/Jasper mix)
Silicon Dioxide (SiO2) with iron oxide inclusions
Agate and Amethyst (Quartz variants)
Silicon Dioxide (SiO2) - Microcrystalline Quartz and Crystalline Quartz
Quartz
Quartz (SiO₂)
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Precious Opal
Hydrated silica (SiO2·nH2O)
Tree Agate
Silicon Dioxide (SiO2) - Dendritic Agate/Chalcedony
Gneiss (Cobble)
Gneiss
Gneiss
Gneiss (High-grade metamorphic rock)
Gold
Native Gold (Au)
Sandstone (Picture Sandstone)
Sandstone (primarily Quartz with Iron Oxide impurities)
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Ironstone Concretion / Limonite Node
Ferruginous Sedimentary Rock (composed primarily of Limonite FeO(OH)·nH2O and Goethite)
Chert or Flint (polished/water-worn)
Chert (a microcrystalline or cryptocrystalline variety of quartz, SiO2). Flint is a specific variety of chert.
Sandstone (Quartz-rich)
Arenite
Gneiss (Banded Gneiss)
Gneiss
Terrazzo (Man-made Composite)
Cementitious or Resin-bound Lithic Composite