Stuller’s Assay Lab technicians ensure our customers receive the highest quality metals every time they buy.

With more than 25 years of experience in this specialized lab, the technicians test the precise elemental content of gold and other metals created in our metals fabrication department. 

We verify that the gold is the correct carat, meeting the legal tolerances for all the FTC guidelines and also that the other elements in that alloy are within their target guidelines.

As metal sheet, rod, or grain is made throughout the day, samples are brought to the lab for testing. To test for gold, the sample is placed in a lead pocket before it heads to the oven. From there, only silver and gold remains in the sample, which is then rolled several times and placed back in an oven. After its final oven trip, an acid bath removes any remaining silver in the sample. The gold sample is weighed one last time for comparison to the original sample. The process is done twice, to two different samples, to ensure the readings are consistent.

Stuller's reputation relies on providing you the proper 14 carat and platinum each and every time and our job is to verify that every grain made into those rings meets those qualifications before it's even made.

For the other metals, the lab uses an X-ray fluorescence machine, which uses computer technology to determine the components in that sample. In less than 3 minutes, the lab can determine the elements of the sample’s surface.

Thanks to our Assay Lab technicians, customers know that they are buying with confidence.