Assayer
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
One whose business it is to make assays of the precious metals.
— Assayer of the king. An officer of the royal mint, appointed by St. 2 Hen. VI. c. 12, wbo received and tested the bullion taken in for coining; also called "assayator regis." Cowell ; Termes de la Ley.