This jet black marble testing stone is perfect for jewelers, hobbyists, and gemologists who need a durable and versatile surface for testing precious metals and gemstones. Made from high-quality black marble and obsidian, this stone provides a smooth, non-porous surface, ensuring accurate and reliable test results.

Measuring 3 inches long, 1.5 inches wide, and 0.5 inches thick, it offers ample space for gold, silver, and platinum testing while remaining compact and easy to handle. The polished finish enhances streak visibility and ease of cleaning, making it an essential tool for professionals and collectors alike.

Designed for scratch tests, acid tests, and other metal authenticity checks, this high-contrast black testing stone ensures clear and consistent results every time. Whether you're working in a jewelry workshop or at home, this premium touchstone is an indispensable tool for verifying the purity of precious metals.