---
product_id: 49635203
title: "GAIN EXPRESS Diamond Tester Pen, Professional Diamond Moissanite Gemstone Tester with UV Ultraviolet Light & Thermal Sensor, Gem Checker Jewelry Tester Diamond Selector for Novice and Expert"
brand: "gain express"
price: "₩227119"
currency: KRW
in_stock: true
reviews_count: 10
category: "Gain Express"
url: https://www.desertcart.kr/products/49635203-gain-express-diamond-tester-pen-professional-diamond-moissanite-gemstone-tester
store_origin: KR
region: South Korea
---

# Accurate diamond/moissanite detection Low battery consumption, AC adaptor ready UV light for fluorescent testing GAIN EXPRESS Diamond Tester Pen, Professional Diamond Moissanite Gemstone Tester with UV Ultraviolet Light & Thermal Sensor, Gem Checker Jewelry Tester Diamond Selector for Novice and Expert

**Brand:** gain express
**Price:** ₩227119
**Availability:** ✅ In Stock

## Summary

> 💎 Test Like a Pro, Shine Like a Boss

## Quick Answers

- **What is this?** GAIN EXPRESS Diamond Tester Pen, Professional Diamond Moissanite Gemstone Tester with UV Ultraviolet Light & Thermal Sensor, Gem Checker Jewelry Tester Diamond Selector for Novice and Expert by gain express
- **How much does it cost?** ₩227119 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.kr](https://www.desertcart.kr/products/49635203-gain-express-diamond-tester-pen-professional-diamond-moissanite-gemstone-tester)

## Best For

- gain express enthusiasts

## Why This Product

- Trusted gain express brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Complete Pro Kit:** Includes vinyl pouch, testing platform, and detailed manual—perfect for novices and experts alike.
- • **Metal Contact Alert:** Audible warnings prevent false readings when touching metal surfaces.
- • **Compact & Power-Savvy:** Lightweight design with low battery use and optional AC adaptor for uninterrupted testing.
- • **Fluorescent UV Testing:** Advanced ultraviolet light reveals gemstone authenticity beyond the surface.
- • **Precision at Your Fingertips:** Instantly identify genuine diamonds down to 2pt with a single button press.

## Overview

The GAIN EXPRESS Diamond Tester Pen is a professional-grade gemstone tester combining thermal sensors and UV light technology to accurately distinguish natural diamonds from simulants like moissanite and cubic zirconia. Designed for both novices and experts, it features a compact, battery-efficient design with audible metal contact alerts and comes complete with a testing platform and carrying pouch.

## Description

Free delivery and returns on all eligible orders. Shop GAIN EXPRESS Diamond Tester Pen, Professional Diamond Moissanite Gemstone Tester with UV Ultraviolet Light & Thermal Sensor, Gem Checker Jewelry Tester Diamond Selector for Novice and Expert.

Review: Good product for the price. - Very easy to use. Good price.
Review: Good product - Worked better than I thought

## Features

- 💎 Reliable diamond selector: This diamond tester is unresponsive to imitation crystals and simulants like cubic zirconia and moissanite, making it the go-to choice for retail jewelers, pawn brokers, and chain stores.
- 💎 Advanced technology: Equipped with ultraviolet light for fluorescent reaction testing, multi-level volume calibration, and audible warning sounds when the probe touches a metal surface.
- 💎 Convenient features: Compact design, low battery consumption, and the option to use an A/C adaptor for extended indoor use.
- 💎 Accurate and precise: With a single button press, it can identify genuine "natural" diamonds and distinguish stones as small as 2pt.
- 💎 Complete set: Comes with a vinyl pouch, testing platform for loose stones, and a comprehensive instruction manual. Brand new and unused.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00MNEB0U0 |
| Batteries Required? | No |
| Batteries included? | No |
| Battery Cell Type | Alkaline |
| Battery description | Batería 9v |
| Best Sellers Rank | 233,322 in DIY & Tools ( See Top 100 in DIY & Tools ) 667 in Multi Testers |
| Customer Reviews | 3.8 3.8 out of 5 stars (150) |
| Date First Available | 5 Sept. 2014 |
| Item Package Quantity | 1 |
| Item Weight | 150 g |
| Item model number | JEM-II |
| Manufacturer | Gain Express Holdings Ltd. |
| Part Number | JEM-II |
| Power Source | Battery Powered |
| Product Dimensions | 17.78 x 7.62 x 5.08 cm; 149.69 g |
| Style | Compact |

## Images

![GAIN EXPRESS Diamond Tester Pen, Professional Diamond Moissanite Gemstone Tester with UV Ultraviolet Light & Thermal Sensor, Gem Checker Jewelry Tester Diamond Selector for Novice and Expert - Image 1](https://m.media-amazon.com/images/I/5123qVp9KAL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Good product for the price.
*by W***M on 3 April 2025*

Very easy to use. Good price.

### ⭐⭐⭐⭐⭐ Good product
*by H***Y on 16 February 2019*

Worked better than I thought

### ⭐⭐⭐⭐ Easy to use
*by W***M on 30 January 2022*

Good materials, look good, easy to use. Just tested on my wife diamond ring, the result is quite good.

## Frequently Bought Together

- Gain Express Diamond Tester Pen, High Accuracy Jewelry Diamond Tester Professional Diamond Selector for Novice and Expert Jewelry Diamond
- Professional Gold, Silver, Platinum Jewelry Testing Kit with Stone Instructions and Box with 30X Eye Loupe Magnifier Precious Metals 10K 14K 18K 24K 999 925 Scrap
- Presidium Instruments Gem Tester II (PGT II) with Assisted Thermal Calibration (ATC) for Identifying Diamonds/Moissanites and Common Colored Gemstones

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**Shop now:** [https://www.desertcart.kr/products/49635203-gain-express-diamond-tester-pen-professional-diamond-moissanite-gemstone-tester](https://www.desertcart.kr/products/49635203-gain-express-diamond-tester-pen-professional-diamond-moissanite-gemstone-tester)

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*Product available on Desertcart South Korea*
*Store origin: KR*
*Last updated: 2026-02-24*