The GemOro PRO-M II Moissanite Tester identifies, detects and separates Moissanite from Diamond and Other Gemstones and Simulants. The engineers at GemOro Superior Instruments have developed the ultimate moissanite tester. Its state-of-the-art digital electronics and features make this tester the industry's most accurate, reliable and popular moissanite tester in its class. This will only tell you if you have moissanite. If you want to know if you have diamonds, you will need to purchase the Gemoro Pro D II in addition to this tester.