Jewelers use a Dark Test Stone to determine the karat of gold, silver, and platinum by scratching the metal on the stone's surface and applying a test acid solution. This technique ensures accurate results and can be further confirmed using test needles for precise karat verification.

Introducing the Jet Black Marble Large & Natural Obsidian Gold Testing Stone, a must-have tool for jewelers, goldsmiths, and appraisers. Designed for professional gold testing, this 6" x 2 1/2" x 1/2" testing stone features a jet-black surface that provides high contrast, allowing for clear and accurate streak analysis.

Why Choose This Gold Testing Stone?

• Unparalleled Elegance: Crafted from jet black marble, this stone features a luxurious and sophisticated appearance, elevating your workspace.
• Natural Marbling: Each stone is one-of-a-kind, boasting unique marbling patterns that enhance its visual appeal.
• Versatile Application: Ideal for gold, silver, and platinum testing, this stone is also perfect for crafts, jewelry making, and artistic projects.
• Premium Quality: Meticulously cut and polished, this stone ensures exceptional durability and precision for accurate testing.
• Stunning Contrast: The deep black surface enhances the visibility of metal streaks, ensuring precise karat identification.

How to Use:

1. Prepare the Stone: Wipe it clean to ensure no residue interferes with the test.
2. Scratch the Metal: Lightly rub the gold, silver, or platinum onto the surface to create a streak.
3. Apply Testing Acid: Use the appropriate test solution to determine the metal's purity.
4. Verify Results: Compare the streak’s reaction to known karat values.

Maintenance Tips:

• Clean regularly with a soft cloth to remove metal residues.
• Store in a dry place to preserve its smooth finish.