Magnifier but it gives higher magnification with less chromatic aberration, although you usually would find cheaper lenses quite useful for general metal inspection purposes. A testing acid and touch stones are also important materials for a jeweler who wants to test authenticity of gold. The Buy Email Database touch stone acts like an abrasive surface and scratches out the surface of the metal being tested.
You rub the metal onto the touch stone and it leaves a visible line on the touch stone surface. Then you drop acid to determine if it is really gold and to determine the karat of the gold. There Buy Email Database are different acid formulas for different karats of gold. For instance Buy Email Database there is one acid tester for an 18K gold and another for a 10K gold. Acids for gold testing come as 10K,
4K, and 18K kit with touch stone. Such kits can be purchased on eBay. Be careful when you are using acids because they can irritate your skin. You should wear protective gloves if Buy Email Database you are doing the testing yourself. When ensuring accuracy of gold testing, you need to know if the acid is working properly. Exposed acids can become inaccurate due to contaminants.