Explanatory notes
… C opper ores and concentrates. The principal ores generally classified in this heading are : (a) Atacamite, natural copper hydroxychloride. (b) Azurite , basic copper carbonate. (c) Bornite (or erubescite), … , copper sulphide. (k) Cuprite , cuprous oxide. (l) Dioptase , copper silicate. (m) Grey copper ore (often …