A member of the serpentine group with textures showing packets of cylinders, scrolls, and tubes, as well as helical or spiral fibers. Chrysotile, ideally Mg₃Si₂O₅(OH)₄, crystallizes in monoclinic symmetry (clinochrysotile) with the fiber axis parallel to X and orthorhombic symmetry with the fiber axis along X (orthochrysotile) or Y (parachrysotile). Polytype stacking for clinochrysotile is either 2M_c1 or 1M_c1, where the number of layers (e.g., 1 or 2) precedes M = monoclinic, subscript c = cylindrical, and subscript 1 is used to distinguish the form from another cylindrical polytype that would otherwise have the same symbol. The orthochrysotile polytype is 2O_c1. Cylindrical structures do not have consistent hydrogen bonding between layers that would be observed in an ideal platy structure, and thus do not conform to the standard polytypes. Fiber dimensions are variable with inner diameters near 70-80 Å and outer diameters reported at 220-270, >350, and 490 Å (the latter value involves synthetic samples). Al, Fe²⁺, and Fe³⁺ may substitute for Mg, and Fe³⁺ may substitute for Si; all substitutions are very limited, but greater than in lizardite. The differences between these substitutions in lizardite vs. chrysotile suggest that in natural systems, lizardite and chrysotile are not sensu stricto polymorphs. Chrysotile, or “white asbestos”, is the asbestosform serpentine and is mined in Russia near the Ural Mountains and in Asbestos, Quebec, Canada.