text: West Mexican smiths worked primarily in copper during the initial period, with some low-arsenic alloys, as well as occasional employment of silver and gold. Lost-wax cast bells were introduced from lower Central America and Colombia during this phase, along with several classes of cold-worked ornaments and hand tools, such as needles and tweezers.  The prototypes for these small, often utilitarian items appear rooted in southern Ecuador and northern Peru. Small copper rings, generally found in burial contexts, are also common to Ecuador and Western Mexico and are abundant during this phase. 
  Excavated assemblages from the initial phase indicate that lost-wax cast bells also occupied a substantial portion of West Mexican artisans' efforts. Unlike similar bells recovered from coastal Ecuador, West Mexican bells were cast, rather than worked, metal. Typically composed of a smooth, suspended metal shell encasing an interior clapper, the West Mexican bells were generally fashioned from copper alloys and bore particular resemblance to bells made in Colombia, Panama and Costa Rica.