Convert from onca [Portuguese] to mace [China]

Unit Definition (onca [Portuguese])
The onça, once, oncia, onza is traditional names for the ounce unit in Romance languages. The Portuguese onça and Spanish onza equal 1/16 libra or about 28.69 grams (1.012 ounce).

Unit Definition (mace [China])
The mace is a traditional Chinese unit for weighing precious metals, especially silver. In the European colonial period, the mace was considered equal to 0.1 tael or liang; this would be 2/15 ounce or about 3.78 grams.