4 Piece Gold Testing Needle Set 10k,14k,18k & .999s To Use With Test Acid Stone

This set is the best available this is made of high quality metal and has 4 different karats 10k,14k,18k & .999s The needles and the item to be tested are rubbed on a test stone and treated with acid to determine a match. All Gold Test Needles are not created equally. Gold test needles are gauges /bench marks to compare unknown gold objects for color reference when using acid or premixed gold test solutions to determine their gold content. Needles are also a necessity for checking premixed test solutions for accuracy and to make sure they have not deteriorated over time. If the test needles are not the correct alloys they will not give you the correct reading. Over the last several years I have noticed that all of the test needles available seem to be imported and are not of the correct alloy. This makes them almost worthless in testing unless you are very knowledgeable on the subject and know how to compensate for the inaccuracy of the import needles. I am not implying that the imports are not marked correctly.I am saying they are not alloyed to mach 8k through 22k gold that most gold jewelry is made of . 14k gold consists of 58.8% gold, about 12.8% silver, 22.9% copper, 3.5% zinc, and .2% cobalt. It is this writer's belief that copper is substituted in lue of some or all of the silver in the imported test needles and for that reason their marks are more copper colored. I have a lot of customers call me and want 8k and 12k solution. I suggest they purchase a set of correctly alloyed test needles then they could identify 8k or 12k gold by applying 10k or 14k solution and will be able to see the slight change in color of the test mark when compared to the 8k or12k test needles. This is not possible if using the imports because the mark is copper tinted before a solution is applied. It is important to recognize that test needles are the heart of any test system that uses acid solutions to test for gold content.