The Presidium Gem Indicator is the only handheld tester in the industry specifically for colored gemstones that helps to indicate up to 31 different types of colored gems based on their thermal conductivity and even features a color input function that allows users to select from a range of common colors, thereby narrowing down the possible results. With an easy-to-read clear digital LED screen, this smart thermal tester also comes with the Presidium patented replaceable probe tip technology, which ensures minimal equipment downtime. The Presidium Gem Indicator is an enhanced and more convenient handheld version of the revolutionary Presidium Gem Tester/Colored Stone Estimator. It distinguishes between diamonds and other colored gemstones using the principles of thermal conductivity. The P.
eBay