Multi-Metal Application - Ideal for testing 10K, 14K, 18K, 22K-24K gold, as well as silver and other precious metals. Simple Testing Process - Apply a drop of acids on the touchstone; real gold remains on the stone, while fake metals dissolve or turn blue. Accurate Gold Purity Testing - Specially designed acids test kit for verifying the gold content in jewelry, coines, bullion, antiques, and collectibles. Easy-to-Read Color Change - Acids changes color based on metal purity, providing quick and reliable results. Essential Tool for Jewelers & Collectors - Compact, portable, and easy to use , in workshops, or on-the-go appraisals., Manufacturer: Akfldms