Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse sedimentary (chemically precipitated) or metamorphic specimens identified by the Rock Identifier community.
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Green Jasper
Silicon Dioxide (SiO2) with iron silicate inclusions
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Chert (specifically Red Chert / Jasper nodule)
Silicon dioxide (SiO2)
Chalcedony (Common Opal/Chert variety)
Silicon Dioxide (SiO2)
Ferruginous Sandstone
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
Quartzite Pebble
Quartzite (SiO2)
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartz
Quartz (SiO₂)
Quartz / Quartzite
Silicon Dioxide (SiO2)
Apatite
Apatite group mineral (e.g., Fluorapatite - Ca5(PO4)3F, Chlorapatite - Ca5(PO4)3Cl, Hydroxylapatite - Ca5(PO4)3(OH))
Quartz
Silicon Dioxide (SiO2)
Magnetite
Magnetite (Fe3O4)
Agate
Silicon dioxide (SiO2)
Quartzite Pebble
Quartzite (primarily SiO2)
Blue Quartz (Dumortierite Quartz)
Silicon Dioxide with Aluminum Borosilicate (SiO2 + AlAl6BSi3O18)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Quartzite Pebble
Quartzite (primarily SiO2)
Yellow Quartzite (Iron-Stained Quartz)
Quartzite (SiO2 with Fe-oxide impurities)
Quartzite
Quartzite (SiO2)
Quartzite Pebbler
Quartzite (SiO2)
Quartzite (River Pebble)
Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Jasper with Agate Inclusions
Silicon Dioxide (SiO2) - variety of Quartz/Chert
Quartz (River Pebble)
Silicon Dioxide (SiO2)
Halite (Rock Salt)
Halite (Sodium Chloride, NaCl)
Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Limonite (Iron-rich Siltstone / Sandstone base)
Hydrous ferric oxide mixture (FeO(OH)·nH2O)
Ferruginous Sandstone
Arenite with Hematite/Limonite cement (SiO2 + Fe2O3)
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Orange Calcite
Calcium Carbonate (CaCO3)
Chert
Microcrystalline silica (SiO2)
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
Porphyritic Andesite
Intermediate Volcanic Rock - Andesite
Quartz Geode
Silicon Dioxide (SiO2)
Aragonite Star Cluster
Aragonite (Calcium Carbonate, CaCO3)
Satin Spar (often marketed as Selenite)
Fibrous Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
Quartz Geode
Quartz (Silicon Dioxide, SiO2)
Quartz Geode
Silicon Dioxide (SiO2) in a Secondary Sedimentary/Volcanic cavity
Carnelian
Carnelian Chalcedony (SiO2)