Allophane
Chemical Formula	Al2O3·SiO21.3-2·H2O2.5-3
Species	Silicates
Mohs Scale	3
Color	White, pale blue to sky-blue, green, brown
Streak	White
Luster	Waxy
Diaphaneity	Transparent, Translucent
Cleavage	None ObservedNone
Fracture	Conchoidal
Crystal Habit：Rarely observed as ring-shaped particles, with diameters of 50 oA, which in three dimensions may represent sections through hollow spherules or polyhedra. As hyaline crusts and masses; stalactites and flowstones.
Geological Setting：A weathering product of volcanic ash. In hydrothermally altered igneous rocks, from the breakdown of feldspars, and in hydrothermal veins, typically related to copper deposits. In sedimentary rocks, including chalk and coal beds.