









💎 Spot the real sparkle before anyone else does!
The GAIN EXPRESS Diamond Tester Pen is a professional-grade gemstone tester designed for both novices and experts. It uses advanced UV fluorescence and thermal sensors to accurately distinguish natural diamonds from simulants like moissanite and cubic zirconia. Compact and energy-efficient, it features audible alerts and multi-level volume calibration, making it an essential tool for jewelers, pawn brokers, and gemstone enthusiasts seeking reliable authenticity verification.






| Item Package Dimensions L x W x H | 6.93 x 2.13 x 1.42 inches |
| Package Weight | 0.14 Kilograms |
| Item Dimensions LxWxH | 7 x 3 x 2 inches |
| Item Weight | 55 Grams |
| Brand Name | Gain Express |
| Country of Origin | Hong Kong |
| Material | Vinyl |
| Manufacturer | Gain Express Holdings Ltd. |
| Part Number | JEM-II |
R**S
"Good and it Works"
This tester is good and it works.
D**.
Very responsible sellers, would buy again
The pen I ordered was delivered the day they said it was suppose to arrive. It's a very good tester and I like it very much
T**T
Not worth your money
Don’t bother
G**E
GOOD
GOOD
A**R
Great product
Work just as described
D**.
Works great
The more you push the tip against your diamond the more accurate it will become
D**R
Would not detect moisinite though .
At this price point a great buy, for novice use, as it was for me.
A**N
What you expext for price, it works
Nothing fancy or above the price I paid. A good one is 300-$500 but for a mobile tester, it fine
Trustpilot
2 weeks ago
1 month ago