A dark stone, that shows results clearly, on which a needle and item to be tested are rubbed. Test acid is normally used to test gold, silver and platinum to determine the carat value of jewelry and watches. This smaller style stone makes it a good choice for a portable gold test kit and offers a high quality surface for your testing chemicals.
- Black testing stone for acid testing
- Use to test gold, silver and platinum
- Measures 2-1/2" x 1-1/2" x 1/2"