Gold Testing Acid Stone Scratch Purity Assay Tester Test Scrap Jewellery Watch

Fine-grain natural gold testing stone measuring 100mm x 53mm, used with testing acid to scratch-test gold and precious metals.

⭐ At a glance

📏 Size: 100mm x 53mm

✅ Suitable for gold, precious metal, jewellery and watch case testing

📦 Includes: 1 x testing stone (acid not included)

✔️ Condition: New

🔧 What it does & how to use

A gold testing stone is a fine-grained rectangular block used alongside gold testing acids to check the purity of gold, silver and other precious metals. It's a staple tool for jewellers, watchmakers, pawnbrokers and collectors checking scrap, jewellery, watch cases and small items before buying, selling or repairing them.

• Scratch a line: Rub the item firmly across the stone's surface to leave a visible streak of metal on the fine-grain face.
• Apply testing acid: Place a drop of the appropriate karat testing acid onto the scratch mark.
• Read the reaction: Observe how quickly the mark dissolves or changes colour to judge the metal's purity.
• Clean between tests: Wipe the stone clean before testing a different item to avoid cross-contamination of results.

⚠️ Please check this listing is for the testing stone only — testing acids and any comparison needles are sold separately.