Dalmatian Stone (commonly called Dalmatian Jasper)
Peralkaline Rock (mixed Feldspar, Quartz, and Arfvedsonite)
Category
Browse sedimentary rock (altered) specimens identified by the Rock Identifier community.
Dalmatian Stone (commonly called Dalmatian Jasper)
Peralkaline Rock (mixed Feldspar, Quartz, and Arfvedsonite)
Gneiss (Cobble)
Gneiss
Quartz Crystal (specifically a small Clear Quartz point)
Silicon Dioxide (SiO2)
Jasper (specifically Brecciated or Agated Jasper)
Silicon Dioxide (SiO2) - Chalcedony with impurities
Chalcedony Nodule (Commonly known as Agate or Chert)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (primarily SiO2 - Silicon Dioxide)
Clear Quartz
Silicon Dioxide (SiO2)
Chert (Field Stone)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Coquina
Biogenic Limestone (CaCO3)
Red Sandstone
Arenite (with Iron Oxide / Hematite cementation)
Bauxite
Bauxite (Mixture including Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))
Sandstone
Arenite (primarily SiO2)
Bauxite
Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)
Glauconitic Sandstone (Greensand)
Glauconitic Quartz Arenite (containing Glauconite, (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)
Ferruginous Sandstone
Arenite with Iron-Oxide cement (primarily Fe2O3 • nH2O)
Chert / Jasper
Microcrystalline Quartz (SiO2)
Travertine (Calcareous Tufa)
Calcium Carbonate (CaCO3)
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Almandine Garnet in Schist Matrix
Almandine - Fe3Al2(SiO4)3
Mookaite Jasper
Silicified Radiolarite (SiO2)
Jasper (likely Ocean Jasper or Variegated Jasper)
Silicon Dioxide (SiO2) with impurities
Jasper with Quartz (Agate/Jasper mix)
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (Cherty Flint/Jasper variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (Jasper variety) with Iron Oxide staining
Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities
Red Jasper (Chert)
Silicon Dioxide (SiO2)
Gneiss Pebble
Gneiss
Chert (and/or Siltstone River Pebble)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Bauxite
Bauxite (mixture of Hydrous Aluminum Oxides)
Gneiss (specifically Granitic Gneiss)
Gneiss (composed primarily of Quartz, Feldspar, and Biotite/Amphibole)
Gneiss
High-grade foliated metamorphic rock
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Gneiss (specifically a weathered Amphibolite or Garnet Gneiss)
Gneiss (complex silicate composition)
Gneiss (with Quartz and Mica)
Gneiss
River Pebbles and Quartz
Mixed Igneous, Sedimentary, and Metamorphic Rocks (Silicon Dioxide SiO2 dominant)
Gneiss
Gneiss (High-grade metamorphic rock)
Pink Opal
Amorphous Hydrous Silica (SiO2·nH2O)
Ironstone with Limonite/Goethite coating
Ferruginous Sedimentary Rock (contains Limonite FeO(OH)·nH2O)
Mookaite Jasper
Siliceous sedimentary rock (variety of Jasper/Chert)
Anthracite Coal
Anthracite (Carbon-based sedimentary-metamorphic rock)
Red Sandstone
Arenite (primarily Quartz SiO₂ with Hematite Fe₂O₃ staining)