Scratch testing involves the use of needles verified as having certain levels of gold and low-grade acid solutions corresponding to each karat level. By treating the pieces with acid and comparing scratches from the needles, the tester can confirm what kind of gold is contained in the piece.
Scratch testing involves the use of needles verified as having certain levels of gold and low-grade acid solutions corresponding to each karat level. By treating the pieces with acid and comparing scratches from the needles, the tester can confirm what kind of gold is contained in the piece.
