
The first desktop instrument that estimates colored gemstones and identifies diamonds, using the principle of thermal properties of gemstones.
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.
Features
- Detachable probe pen with retractable thermoelectric probe tip that ensures constant pressure between probe and gemstone
- Industry’s thinnest probe tip (0.6mm) for testing diamonds as small as 0.02ct
- Metal alert buzzer to ensure that probe tip is in contact with gemstone during testing
- Clear and easy-to-read analog dial
- Can differentiate between 15 types of gemstones
- Built-in diamond and simulant test discs for reference

Benefits
- 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
- Simple and easy to use
- Runs on batteries

Specifications
Power & Battery
2 x AAA alkaline batteries (approximately 3 hours of continuous use)
AC port to be used with appropriate Presidium Power Adaptor (included)
Recommended Operating Conditions
Optimal Operating Temperature: 18°C – 27°C (65°F – 80°F)
Storage Temperature: 10°C – 51°C (50°F – 124°F)
Dimensions & Weight
Length: 165mm (6.50 inches)
Width: 77mm (3.03 inches)
Height:77mm (3.03 inches)
Weight (without batteries): 260grams (9.17 oz)