Energy Dispersive X-Ray Fluorescence, sometimes referred to as X-Ray Fluorescence spectroscopy. This equipment is most commonly seen in metals testing, but more sophisticated versions are utilized in trace element analysis of gemstones. ED XRF identifies the elements (atoms) present in a material. Larger, heavier elements are most easily identified – such as heavy metals – but our more sensitive instrument is calibrated to detect lighter elements seen in gemstones, as well as those responsible for the color. This provides useful analysis and comparison of trace element chemistry often leading to determinations regarding origin, treatments, and growth conditions. Never used as a sole-identifier of a gem material, it often provides the missing piece to more difficult puzzles.
Here is a typical XRF qualitative readout seen on our equipment. Data seen was taken of a sheelite. For more information on this particular readout please see the article: http://stonegrouplabs.com/wp/wp-content/uploads/2015/02/JoG-scheelite.pdf
Radiation in Gemstones
Pictured along with our XRF equipment is our Geiger counter. Many gems and minerals such as Zircon and Turquoise can contain radioactive material, enough to create enough concern for the wearer. We routinely screen any problematic, unknown, or high risk stones for radioactivity.
See basic readout and example:
Turquoise cab silver ring displaying ~35X above background radiation.
Yellow discoloration on surface is uranium.(distinct 13.61 KeV alpha)
© Stone Group Labs, LLC 2019