Testing needles - 8, 10, 12, 14, 18 KT gold

Needles for gold fineness testing

Needle set:

•  8 K ( 333 / 0.333 ) 33.3 % gold
• 10 K ( 417 / 0.417 ) 41.7 % gold
• 12 K ( 500 / 0.500 ) 50.0 % gold
• 14 K ( 585 / 0.585 ) 58.5 % gold
• 18 K ( 750 / 0.750 ) 75.0 % gold

For making marks on testing stone and comparative testing. Each needle is made of pure gold with copper and silver. Needles made with the highest accuracy of gold fineness grades.

How to test gold using the comparative method? 

The test requires:

• test needles or a test star
• gold testing stone - lidite
• Test fluids

The gold alloy (product) whose purity we want to check is used to drawn marks on the surface of the testing stone. Select the appropriate needle fineness according to the expected grade of the examined alloy and make a parallel mark, e.g. if there 585 is marked on the product, then use the 585 needle we make a mark on lidite. A small amount of testing fluid is applied to the resulting marks and the excess is removed (e.g. with blotting paper) after a suitable period of time. 

Afterwards, visually compare the resulting colour changes of the tested alloy marks with the marks from the needle.
Darker marks indicate a lower gold content. By obtaining the same shade of colour we can conclude that the examined alloy has the same fineness as the test needle.
The test can be repeated or more marks can be made using several test needles of different grades.

NOTE ! Keep test needles clean, away from acids and test fluids.

Instructions for use are included in the package and are available in the annex below.

Instructional video - How to test gold on a testing stone