This EASY to use genuine GTE 2x2 white and black test stones are a great tool to use with will Gold, Silver, and Platinum testing solutions. Simply scratch the test stone with your jewelry and apply a drop of the acid to the stone and watch the results appear! Solutions sold separately. This listing includes: - GTE 2''x2'' Black Test Stone New in Box with Rubber backing to ensure non-slip desktop testing! Can be used over a thousand times, simply clean with baking soda/water between uses. - GTE 2''x2'' White Test Stone New in Box with Rubber backing to ensure non-slip desktop testing! Works great with the silver test acid. Stones can be used over a 100 times, simply clean with baking soda/water between uses. - (1) Easy to follow instruction booklet with color chart A MUST-HAVE for anyone who invests in gold, silver, or platinum! NOTE: *Solutions sold separately*