Best Jewelry Diamond Testers of 2025

“I recently got this diamond tester pen, and I couldn't be more happy with it. As someone who loves jewelry, this tool has made identifying genuine diamonds, moissanite, and CZ a breeze. It offers precise readings that help me differentiate effortlessly. The pen is incredibly easy to use and fits comfortably in my hand. I appreciate how portable it is; I can take it anywhere and test stones on the go. Highly, highly recommended!”

“I recently purchased the HMKIS Diamond Tester Pen with a 60X Mini LED Magnifying glass. While it offers some functionality, it has a few limitations. The diamond tester pen is compact and easy to use, providing a quick indication of whether a stone is real. However, the accuracy is questionable, and I found the build quality a bit flimsy. The instructions are lacking detail for new users. Overall, it’s an average set, suitable for beginners.”

“I use this tester all the time for gems I dig while metal detecting. It’s easy to use, but I learned that I shouldn’t let the point touch the metal mount, or I’ll get a false reading. So far, it has been totally accurate and a great tool for my needs.”

"I always wanted a tester, so I bought this one to check some old jewelry. It was very accurate when testing real diamonds that we already knew about. Plus, it's super easy to use!"

"This tester seems to work well and is cheap. I just made sure to do my research to avoid any possible mistakes. So far, I have had no issues and I love it!"

"I confirmed that this tester is effective on real natural diamonds and rubies, proving its reliability for checking if a diamond is fake."

"I wanted a tester for thrifting, and this one works just as well as my expensive one. It's very easy to use and accurate, plus the quality is great with a bag to protect the tip."

"I've tested diamonds and cubic zirconia, and this device is only about 50% accurate. It sometimes identifies diamonds even when there are none."

"I needed to verify my diamond jewelry, and this device confirmed all my diamonds were genuine. Just remember to set the indicator to bar 4 and get a 9v battery, as it's not included."

"I found that all pieces worked as stated. The portable microscope was particularly impressive; I could actually read certification numbers on the girdles of the diamonds. Amazing! The diamond tester reminded me of the first versions available but had some limitations with Moissanite."

"I noticed the magnifying eyepiece with LED light is made from cheap plastic and is held together with glue. The scale also feels low quality, and unfortunately, the diamond tester doesn't work properly."

"This product has been a great learning tool for my daughter. She is really enjoying it, and it’s a fantastic beginner package!"

"I needed this after leaving my ring with the jeweler, and I'm relieved to confirm the stones are real."

"It took a little practice, but it works well. Arrived quickly and included everything as advertised."

"Unfortunately, I found this to be ineffective for checking diamonds. I regret not investing in a more reliable tester."

"I really like this set. I chose it primarily for the diamond tester, and I'm pleasantly surprised by the mini magnifying tool and the mini jewelry scale. To use the diamond tester, I learned to set it to Level 4 to warm it up, then remove the cap and hold it upright against the diamond or gemstone. My sapphire test was successful, registering a 7 using just the basic instructions. The mini magnifier will definitely come in handy for checking currency at my garage sale in the fall."

"The scale is impressively accurate and user-friendly. While the other tools are interesting, I can't test them since I don't have any diamonds."

“I found what I thought was a diamond in the parking lot at Walmart. It cut glass, but I learned that lab-created diamonds can do the same. I decided to buy this tool to avoid being scammed when I buy second-hand jewelry. I tested it on one ring and it confirmed it was a genuine diamond, but the 'diamond' I found had a low reading, meaning it wasn't real. It was disappointing, but I'm grateful I could check. I highly recommend this tool for anyone interested in gems.”

“I had my last tester for eight years. Unfortunately, someone borrowed it and didn’t return it, so I purchased this one with some hesitation due to mixed reviews. Thankfully, it works well! I use it to test for moissanite too, as genuine moissanite can test as diamond. I've had issues with sellers on Amazon claiming their rings were moissanite when they weren't. Only the MOOSEA brand has proven genuine for me, and I found great prices here!”

“I followed the instructions carefully since I have some knowledge about gems. However, I wasn’t getting readings for stones I know are legit. Additionally, the bag had a jagged piece of plastic that I was unsure about. I’m returning this product as it didn’t operate correctly for me. One star for trying and one star for the nice instructions that didn’t help with the product.”

"I purchased this to ensure my mall jewelry was authentic. Following the directions meticulously, I tested it on both real and fake items, and I’m pleased to say it validated my jewelry!"

"Knowing that I’m getting what I pay for in my jewelry gives me peace of mind, and I’m happy to report that ZALES JEWELRY STORES have passed the test!"

"This tool is very sensitive and took me a while to learn how to use it properly, but I appreciate the precision it offers."

"I purchased this tool to evaluate some jewelry, including diamond earrings. I found a few nice diamond studs and if I sell them, the tool will pay for itself. I'd definitely buy this again if needed."

"This device is incredibly easy to use and gives accurate results. I’ve found over $4000 worth of rings for less than $100 at second-hand stores and yard sales!"

"Initially, I found it a bit hard to use, but after a couple of tries, I got the hang of it. It's a great tool for anyone learning about jewelry."

"I recently bought the Diamond Tester Pen and the Mini Jewelry Scale. I couldn't be happier with my decision! The diamond tester is user-friendly and provides accurate results, which is essential for verifying my jewelry. It gives quick readings, allowing me to assess my pieces confidently. The scale is compact and offers precise measurements down to 0.01g, making it incredibly useful for weighing my precious stones. These tools are of high quality and have truly exceeded my expectations. I highly recommend them to anyone serious about jewelry!"

"I was looking for an inexpensive handheld diamond tester, and this one works just as described. It came with a battery, which was a nice surprise. The tester includes a case that exceeded my expectations in quality. Honestly, I’m a bit shocked at the value I received for the price, and I assure you I wasn’t paid for this review!"

"This product is very easy to use and has helped me test moissanite stones effectively. Every item I bought from Amazon that was advertised as moissanite tested positive, while items from other sites didn’t. This has given me much more confidence in my purchases from Amazon."