Practical Acid Kit Silver Platinum Gold Testing Touchstone Jewelry Tool SetFeatures: This kit is used to verify the gold content in items Ideal for testing jewelry, coins, antique gold, silver, platinum collectibles, and more This solution works for testing any gold which you believe to be 10K, 14K, 18K, 22-24K, silver, and platinum pure. Acid changes color based on purity. Very easy to use. Specification:Material: High purity Graphite Stone & Acid Testing WaterGraphite Stone Size: Approx. 4.1 * 1.1 * 7.2cm / 1.61 * 0.43 * 2.83inchAcid Testing Water Size: Approx. 3 * 1.2 * 4.7cm / 1.18 * 0.47 * 1.85inchTotal Weight: 90gType: Jewelry Tools & EquipmentsPackage List:1 * Graphite Stone3ml * Acid Testing WaterNote:How to use:If you want test your gold ring is real or not, just need rub black stone, and leave a small sample on stoneApply a drop of this solution to a small sample of the item to be tested onto the test stone.Then the real gold will stay on the touchstone, false one will be dissolved or oxidized to blueIf the sample disappears, then the item is below the karat of the solution.Our products are made with the highest quality materials and are designed to provide you with the best possible user experience. We strive to ship out all orders within three days of purchase, and the estimated delivery time is 8-15 days.When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specificationsWe want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don''t hesitate to contact us. We are here to help and will do our best to assist you.Thank you for choosing our product. We hope you enjoy it