This large size gold and silver natural testing stone will last hundred of acid tests. Precious metal acid testing stone is used in conjunction with test acids to determine the karat value and authenticity of jewelry and other gold, silver and platinum objects. This 6" X 3" X 0.375" Inches stone comes in a handy hard wood storage case with a magnetic closure, not only allowing you to store your stone safely without damage, but provides a professional presentation when testing clients gold and silver. Stone is removable to be cleaned and to allow use of both sides. To use stone simply scratch the piece that you are testing on stone, then use the appropriate test needle and solution to determine karat value. Test acids sold separately.
- Large natural acid testing stone provides excellent surface for testing authenticity and karat value of precious metals
- Comes in handy wood box for storage with magnetic closure
- Stone is removable from storage case for cleaning and to allow use of both sides
- Stone dimensions are 6" X 3" X 0.375" Inches (182.4 X 76.2 X 9.5mm)
- Thickness: 0.375" Inches (9.5mm)