The monton is a traditional Spanish-colonial weight unit used in Mexican and South American silver mining to measure batches of ore for amalgamation. Its exact mass varied by mining district, typically ranging from 1,800 to 3,200 Spanish pounds. Mill operators used it to calculate the precise amount of mercury and reagents needed for the patio process.
Heard on the job
The mill processed fifty montons of silver ore from the lower levels this week.
Insider tip
Because the monton varied wildly from Zacatecas to Guanajuato, historic production records must be converted using the specific local equivalent.