Explanatory notes
… and zircon sands, zirconium silicates. (When in the form of a precious stone, zircon falls in heading 71.03 .) The … tantalite and niobite (columbite) (i.e., tantalo‑niobate of iron and manganese). The principal vanadium ores … in this heading are : (a) Descloizite, basic vanadate of lead and zinc. (b) Patronite, vanadium sulphide. (c) …