Thanks for the tips they will come in handy. FYI, I received a catalog from K.B. Slocum Books yesterday, and in their catalog, they have a 3 in 1 test kit for gold, Silver, and diamonds. It is 29.95 + 2.50 S&H. The 1st 2 are chemical test you can apply and the third uses a Sapphire test surface which is supposed to work better than a glass test since zirconia will pass a glass test but not a sapphire test. when I am in the position to need this , I may give it a try.