Large gold testing set

The set is used to test yellow gold of several fineness grades

The set includes:

- Gold test needles, including 333 (8 carat), 417 (10 carat), 500 (12 carat), 585 (14 carat), 750 (18 carat) gold

- Lidite testing stone 200 x 75 x 12 mm

- 7 test fluids - No. 1, 2, No. 3 (gold chloride 0.18 g), 4, 5, 6 and 7.

Approximate method for testing gold on a test stone 

Products required:

• Test needles / test star 
• Lidite test stone
• Test fluids

The gold alloy (product) whose purity is being determined is used to create a mark on the surface of the test stone. Match the needle grade to the expected grade of the tested alloy and create a parallel mark. Apply a small amount of the test fluid crosswise over the resulting marks and remove the excess (e.g. with blotting paper) after a suitable time has elapsed. 
Then visually compare the resulting colours of the tested alloy and the needle marks. 
Darker sample marks of the test piece compared to the test needle indicate a lower gold content. Obtaining the same shade of colour establishes that the tested alloy has the purity of the test needle. 
The test can be repeated or more marks can be made using several test needles of different fineness until identical colours of the marks are obtained.

Full instructions for the use of the test liquids are included with the products and available as an appendix below.

NOTE ! Product for professional use only. Sold only to companies.

Instructional video - How to test gold on a testing stone