Service Detail

Authentication & assaying of precious metals

Sky Bullion Assay Laboratory is an integral part of the business. Our mission is to determine and verify the four primary precious metals used in the jewelry industry (Gold, Silver, Platinum, and Palladium), which are contained in materials such as dore bars, alluvial gold, and jewelry alloys and scraps and jewelry waste.

We use internationally accepted procedures of Fire Assay by fusion and cupellation together with Atomic Absorption Spectrometry.

We also use the latest X-Ray Fluorescence (XRF) technology which alloys the Assay Laboratory to perform a pre-screening test and quick verification of unknown alloys submitted by customers for refining.

This is critical for deciding the correct inquartation with fine silver prior to actual fire assaying. Inquartation is the method that ensures the best parting or separation of the target elements, resulting in the accurate determination of the precious metals.

Our offices also have XRF machines, so quick checks and confirmations can be done if the submitted material is suitable for analysis using XRF.



The weighing, roasting, and melting of the different types of materials for refining, follow internationally recognized sample preparation techniques to enable the extraction of a genuinely representative sample for analysis. In addition, all principal and spent refinery process solutions are monitored by sampling and assaying.



Frequently Asked question

Upon completion, you should receive an assay card or an assay certificate. This should have details confirming the process and results. Expect such information as date, purity, weight, and dimensions, as well as a unique serial number and mint mark.

Many consider direct methods as the most accurate, as they test the metals’ composition. However, this usually requires melting or dissolving some or all of the product in question. Any markings or stamping will obviously disappear or be marred. So, while this is an excellent method of bullion bars, it may not be the best method for commemorative coins, since the stamps, which may be integral to the value, are likely to be damaged.

We would like to believe everyone who says that their gold bullion bars are pure, but we should not. And as much as we would like all our customers to take our word on the quality of the bullion, we know that expert analysis and certification is the only option for providing our customers with the levels of confidence they need to feel safe.

  • Adress 445 S.Figueroa Street Ste 3100, Los Angeles CA 90071
  • FAX
  • Phone+1 323-833-0257