【Testing Principle】Use the corners of the ore to scratch the sample to be tested, and judge the hardness of the sample based on whether there are scratches on the sample: if there are scratches, it means that the hardness of the sample is lower than the hardness of the hardness pen. 【Hardness Grading】This tool incorporates the mineral hardness scale ranging from 3 to 9, including materials such as Calcite (3) and Corundum (9). The innovative multi-faceted tip design greatly enhances operational convenience while ensuring precise measurements across different materials, making it an essential tool for professionals. 【Test Grade】Calcite-3, Fluorite-4, Apatite-5, Orthoclase-6, Quartz-7, Topaz-8, Corundum-9. The test gemstone at the tip of the hardness test is a carefully processed multi-faceted shape, which is more convenient and practical to use. 【User-Friendly Design】Designed with an ergonomic multi-faceted testing tip, this hardness tester provides a comfortable grip for easy operation. Its innovative design ensures that both professionals and enthusiasts can conduct reliable tests effortlessly, making it an ideal tool for everyday use in various settings. 【Wide Application】This hardness test pen is applicable for gemstone, ceramic tile, floor, glass, mobile phone screen, mineral, concrete, etc.thicknesses, including materials such as polyethylene, polyester, and aluminum foil.