Reduced!Metal Detection Test Stones Gold Goldsmithing Tools Acid Making Platinum Scratch

Description: This acid test stones is used to verify the gold content in items. Acid changes color based on purity, very easy to use. Perfect for testing jewelry, coins, antique gold, silver, platinum collectibles. The natural black stone is particularly resistant to acidity, and the gold color is particularly easy to rub on the stone. Specification: Product name:Test Stones Color: Dark grey Material:Stone Type:Common,Superior (small) Size: (About)Common:4.4*6.9cm/Superior (small):4*7.5cm Package included: 1PC * Test Stones Note: Transition: 1cm=10mm=0.39inch 1. Due to the light and screen difference, the items color may be slightly different from the pictures. 2. Please allow 0.5-2 cm differences due to manual measurement.