Presidium  gem tester

A light and portable instrument that instantly identifies diamonds and most colored gemstones based on their thermal properties.

Presidium Gemstone Tester / Colored Stone Estimator is the only colored gemstone thermal tester in the industry. It provides a quick and easy way to identify diamonds and separate common colored gemstones from one another based on their thermal conductivity. Coated gemstones can also be generally tested with the PGT/CSE.
The Presidium Gem Tester / Colored Stone Estimator has a retractable probe tip that ensures consistent pressure against the gemstone during testing for more reliable results. With the industry’s thinnest probe tip size of 0.6mm, PGT/CSE tests diamonds as small as 0.02ct.

*Does not differentiate between natural and synthetic colored gemstones.


• Identifies diamonds and most colored gemstones
• Tests both polished and unpolished gemstones
• Tests gemstones as small as 0.02ct
• Consistent and reliable results every time
• No waiting time between tests
• Clear and visible display for ease of reading measurements
• Simple and easy to use
• Light and portable tester that can be used anywhere
Power and Battery