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The Efficacy of Precious Metal Assays

At MGS, we offer a wide range of assay services. Since they all do the same thing in the end (determine precious metal purity), some of our customers can be confused about the differences between them and which is best for their particular lot. Here, we’ll lay out the assays we offer to help you figure out which is best for your situation.

Hand/Scratch Test – The scratch test is fast, accurate, and non-destructive. It is best for when you have many scrap pieces to go through, or if the item being assayed has a lot of intrinsic value. It’s accurate within at least 20 parts per thousand. It’s not recommended for use on bullion or white gold items.

X-ray Fluorescence – This test is very accurate and produces computer-printed results, which are handy for authentication purposes. An X-ray assay works well on samples with large flat surfaces. However, it is not recommended for testing items with chemical surface treatment or electroplating. These can give false results in the analysis because only the outermost surface is tested.

Fire Assay – If you want the greatest accuracy, the fire assay can’t be beat. However, it can take more than a day to complete because the sample needs to be melted down as part of the test. A fire assay is best for getting the most value out of large scrap lots. At MGS, we have a $25 charge on fire assays.

Ultrasound Assay – This assay uses an ultrasonic pulse on a sample to detect changes in the consistency of the metal. It is recommended for use on pure samples of uniform structure. This makes it the ideal test for authenticating bullion.

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