GemTrue APEX is a portable diamond verification instrument for loose and mounted stones designed to separate natural diamonds from synthetic diamonds and diamond simulants. It has a dual-probe tip that measures thermal conductivity and UV light absorption to determine stone type. GemTrue APEX is manually operated but gives an automatic result on its built-in display.
Weight: 0.05 ct+
Size: 2.5 mm +
Colour: D-M (D-J tested by ASSURE)
Shape: All
Diamond Simulants: Yes
Mounted Stones: Yes
Key performance metrics measured for the APEX with the ASSURE 2.0 Primary Loose Stone Sample:
Diamond False Positive Rate (optimal rate 0%): 0%
Diamond Referral Rate (optimal rate 0%): 6.9%
Diamond Accuracy Rate (optimal rate 100%): 93.1%
The Primary Loose Stone Sample was tested three times and consisted of 350 loose diamonds, 100 loose synthetic diamonds and 50 loose diamond simulants in D-J color range. Only stones with a minimum girdle diameter of 0.05 ct were tested.
The measured test speed for the APEX was 236 stones per hour.
Key performance metrics measured for the APEX with the ASSURE 2.0 Primary Mounted Stone Sample:
Diamond False Positive Rate (optimal rate 0%): 0%
Diamond Referral Rate (optimal rate 0%): 4.1%
Diamond Accuracy Rate (optimal rate 100%): 92.6%
The Primary Mounted Stone Sample consists of jewelry pieces with open-back settings. The stones are a mix of diamonds, laboratory grown diamonds and diamond simulants in the D-J colour range. Only stones with a minimum girdle diameter of 2.5 mm were tested.
Automated Feed: No
Automated Results: Yes
Automated Dispense: No
Detect or Refer (Synthetic Diamonds): Refer*
Detect or Refer (Diamond Simulants): Detect
Multiple Stones at Once: No
Training Required: No (User manual provided with device)
* stones classified as Type IIa/CVD/HPHT are considered referrals and should be submitted for further testing.
The probe tip should be held at an upright position 90 degrees perpendicular to the table of the gemstone. The user then fully depresses the tip applying constant pressure until the result appears on the screen. Wait 10-15 seconds between tests on the same stone to ensure stone doesn’t heat up. User must always ensure the probe tip is kept clean, and when necessary it should be cleaned with a microfiber cloth.
The instrument makes a measurement and displays one of the following results:
Stones classified as Type IIa/CVD/HPHT are considered referrals and should be submitted for further testing. Stones classified as Moissanite, Simulant and CZ are all considered diamond simulants for the purposes of ASSURE testing. APEX is designed to test round brilliant cut stones; fancy-shaped stones may give inaccurate results.
Size: 4.0 cm (W) x 18.0 cm (L) x 2.5 cm (H)
Weight: 0.13 kg
Price: 1,099 USD (Jan 2026)
GemTrue Co., Ltd.
sales@gemtrue.com
+852 6934 7695
ASSURE Tested Dec 2025
