Banded Gneiss
Gneiss (Metamorphic Rock)
Category
Browse sedimentary rock (cryptocrystalline quartz) specimens identified by the Rock Identifier community.
Banded Gneiss
Gneiss (Metamorphic Rock)
Granitic Gneiss
Gneiss (Metamorphic Rock)
Petrified Wood
Fossilized wood / Silicified wood
Gneiss
Gneiss (High-grade Regional Metamorphism)
Herkimer Diamond in Matrix
Quartz (SiO2) in Dolostone (CaMg(CO3)2)
Jasper (Yellow/Brown variety)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 staining)
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)
Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein
Dalmatian Jasper
Dalmatian Stone (comprised of Feldspar, Quartz, and Arfvedsonite)
Sandstone
Arenicola (comprising mostly Quartz, SiO2)
Limonite/Goethite on Shale
Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock
Jasper Conglomerate (specifically Puddingstone)
Jasper Conglomerate (Siliceous sedimentary rock)
Chert (often called Flint or River Stone)
Chert (SiO2)
Sandstone with Iron Oxide (Limonite/Hematite)
Ferruginous Sandstone (SiO2 with FeO(OH)·nH2O)
Ferruginous Sandstone
Clastic sedimentary rock (primarily Quartz with Iron Oxide cement)
Sandstone with Foliose Lichen
Arenite (Rock matrix) with Xanthoparmelia or Flavoparmelia (Lichen genus)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Jasper and Yellow Chert (Tumbled)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Quartz Geode (Cracked Open Fragment)
Silicon Dioxide (SiO2)
Gneiss (with Mica and Quartz)
Gneissic Metamorphic Rock
Sandstone
Arenite (primarily Quartz Arenite)
Sandstone (Weathered Cobble)
Clastic Sedimentary Rock (primarily SiO2)
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Quartz Geode
Silicon Dioxide (SiO2)
Green Chalcedony (likely Green Agate or Chrysoprase)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Sandstone (likely Ferruginous)
Arenite (SiO2 based with Fe2O3/FeO(OH) cement)
Red Sandstone
Clastic Terrigenous Sedimentary Rock (typically Hematitic Quartz Arenite or Arkose)
Quartz with impurities or Host Rock
SiO2 (Silicon Dioxide) with mixed silicates
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Sandstone Concretion with Quartz Center
Sedimentary Clastic Rock (SiO2 matrix with Quartz core)
Jasper (Iron-stained)
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartz in Matrix (possibly Basalt or Siltstone host)
Silicon Dioxide (SiO2) in Host Rock
Sandstone with Quartz Veining
Arenite with hydrothermal quartz (SiO2)
Sandstone (Quartz-rich)
Arenite (composed primarily of SiO2)
Mixed Tumbled Gemstones and River Rocks
Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)
Banded Iron Formation (BIF)
Banded Iron Formation
Jasper, possibly Brecciated Jasper or Ocean Jasper due to patterns and color
Silicon Dioxide (SiO2), a variety of Chalcedony
Concretion with Quartz Veining
Septarian Concretion (CaCO3 / SiO2)