Sandstone (Wonderstone)
Silicified Sandstone / Orthoquartzite with Liesegang rings
Category
Browse sedimentary rock (technically a variety of chalcedony) specimens identified by the Rock Identifier community.
Sandstone (Wonderstone)
Silicified Sandstone / Orthoquartzite with Liesegang rings
Banded Chert (River Siltstone)
Microcrystalline Quartz (SiO2)
Chert (Tan/Yellow variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Turritella Agate (Calligrapher Stone)
Silicified Elimia tenera (Chalcedony/Quartz)
Chert
Chert (microcrystalline quartz)
Yellow Quartz (Chalcedony)
Quartz / Chalcedony (Silicon Dioxide, SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Limonite and Goethite (Ironstone)
Hydrous Iron Oxide Mixture (FeO(OH)·nH2O)
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
Precious Opal
Hydrated Silica (SiO2·nH2O)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with microcrystalline structure
Chert (Basanite variety) with Quartz Vein
Microcrystalline Quartz (SiO2)
Chalcedony with Matrix
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Nodule)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Quartz (likely Milky Quartz)
Quartz (SiO₂ - Silicon Dioxide)
Petrified Wood
Silicified wood (Quartz/Chalcedony)
Green Kyanite
Kyanite (Al2SiO5)
Jasper
Silicon dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Lake Superior Agate
Banded Chalcedony (Silicon Dioxide / SiO2)
Quartz (likely Rose Quartz or Milky Quartz based on color)
Quartz (SiO2 - Silicon Dioxide)
Desert Rose
Gypsum (variety Selenite) - CaSO4·2H2O
Shale
Shale (Lutite)
Shale
Fissile mudrock (composed primarily of clay minerals and quartz)
Chalcedony Geode Fragment
Microcrystalline Quartz (SiO2)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Quartz (likely) or a Quartzite Pebble
Silicon dioxide (SiO2) for quartz. If it's quartzite, it's a metamorphic rock primarily composed of quartz.
Milky Quartz
Silicon Dioxide (SiO2)
Shale
Clastic sedimentary rock (primarily clay and silt minerals)
Milky Quartz
Silicon Dioxide (SiO2)
Sandstone (likely Graywacke or Lithic Sandstone)
Arenite / Wacke (SiO2 based with lithic fragments)
Labradorite
(Ca, Na)(Al, Si)4O8
Chert (Field Stone)
Chert (SiO2)
Quartz (likely a form of massive or vein quartz)
Quartz (SiO₂)
Agate Geode
Chalcedony (SiO2 - Silicon Dioxide)
Jasper with Agate and Quartz Inclusions
Silicon Dioxide (SiO2) - Chalcedony / Quartz aggregate
Chert (Nodular or Massive Variety)
Cryptocrystalline Quartz (SiO2)
Chalcedony with Druzy Quartz Geode
Silicon Dioxide (SiO2)