Stone for testing gold with test acid.

Dimensions: 200 x 100 x 12 mm

Testing with stone:

• Use the item for testing to make a mark of 3-4 cm on the stone.
• Apply a drop of the 8 ct. test acid.
• If the mark is unchanged, the fine gold content must be higher. Apply a drop of the 14 ct. test acid etc.
• When the mark rises, the fine gold content matches the fine gold content noted on the test acid.
• Clean the stone after use with kontrastol.