GTE 2"x2" Black Jewelry Testing Stone with Non-Slip Rubber Backing Perfect for Gold, Silver, and Platinum Testing Upgrade your testing setup with this premium-quality 2"x2" black testing stone by GTE. Designed for precision and convenience, this stone is ideal for use with gold, silver, and platinum acid testing solutions. ? Features: Professional-Grade Surface ? Smooth black stone ensures clear, accurate metal streaks for easy testing. Compact 2"x2" Size ? Fits comfortably on any workspace or testing kit. Non-Slip Rubber Backing ? Prevents movement during testing, keeping your desktop safe and your hands steady. Durable Long-Lasting ? Built for repeated use with acids and testing needles. ? Use With: Gold testing acids (9K?24K) Silver testing solution Platinum testing solution Perfect for jewelers, appraisers, coin collectors, and metal enthusiasts alike. Whether you?re at home or in the shop, GTE?s black testing stone offers a stable, professional surface for reliable results.