Pre-Mixed Test Acids
Pre-mixed gold, silver, and platinum test acids are available for those who do not wish to mix and handle acids. Generally a selection of these pre-mixed test acids are kept on hand to test for a variety of karats and metals. These acids can be used on test stones or directly on jewelry.
Using Pre-Mixed Acids with a Test Stone
Rub the jewelry on the test stone using firm strokes (two forward and two back) so that a very noticeable streak of metal is left on the stone
Apply a drop of the pre-mixed acid to the center of the streak:
Find a place on the piece of jewelry where you can file a small groove without ruining the jewelry - the intent is to penetrate the thin surface layer of plated metal ( if it is plated). Try testing behind a link of a chain if you can - beware that it is not uncommon to use karat gold for clasps on chains that are only plated with gold. Apply a drop of pre-mixed test acid in the small groove that you filed. Note the color changes if any ( as above when testing on a stone)
Most jewelry pieces have areas of wear that can be good places to test. Occasionally the wear is sufficient to remove any plating and testing these areas without filing can confirm that the jewelry is a lower karat that the test acid. If you do try this and there is no color change, file a small groove and try again to be sure.
If the metal streak noticeably changes color or disappears than the metal is less than the test acid karat.
If the metal streak changes color only very slightly, then it has the same karat as the test acid.
If the metal streak does not change at all, than it has a higher karat than the acid.
Example: When using a 14K test acid, a 12K gold streak will exhibit a large, change color change or completely disappear, a 14K gold streak may have a very slight color change, and if the gold is higher than the 14K it will not change at all.
Using Pre-Mixed Acids on Jewelry
Test Acids come in Easy-to-use plastic bottles with, color-coded labels. Use with test stones or on a portion of the jewelry that has been sufficiently filed to reveal the base metal ( if any ). Pre-mixed test acids are available for 10K, 14K, 18k, 22K gold, platinum and silver.
The test stone can be used to test a streak of metal laid down from the jewelry, or a small groove can be filed on an inconspicuous place of the jewelry and tested.
Rub the article on the test stone and apply a drop of Platinum. A platinum mark will remain the same white color with no reaction. If the mark is dissolved it is not Platinum.
Rub the article on the test stone and apply a drop of Silver. The color reaction with the solution will be as follows ( take in to consideration that the background of the test stone is black and most Mexican silver generally contains less than 90% fine silver)
925 Silver - Dark Red
800 Silver - Brown
500 Silver - Green
Note: With the silver solution, it is possible to test directly on the piece being tested, however, the solution will dull the finish on the piece and leave a mark where the acid was placed.
KEEP OUT OF REACH OF CHILDREN
This product was added to our catalog on Monday 03 March, 2008.