【Mohs Hardness Tester】Made of crystal, the value is accurate. There are 5 hardness pens in the box. Material: pen tip (5# apatite; 6# orthoclase; 7# quartz; 8# topaz; 9# corundum). Good texture and exquisite appearance. 【Test Number】5-apatite, 6-orthoclase, 7-quartz, 8-topaz, 9-corundum. The five minerals are inlaid on five metal rods. This hardness tester is suitable for gems, ceramic tiles, floors, glass, mobile phone screens, minerals, concrete, etc. 【Indirect Visual Inspection Method】The hardness of the gemstone can be reflected by the smoothness of the processed facet and the sharpness of the edge. Under magnifying glass, you can see that the facets of gemstones of different hardness are smooth, flat, and sharp. Indirect visual inspection method is a non-destructive approximate hardness identification method. 【Exceptional Quality】We offer you this impeccable Mohs hardness tester. The hardness test kit has been carefully machined into a multi-faceted shape, making it easier to use and more durable. Well-machined multi-faceted, convenient and durable; easy to carry, complete variety 【Range of Applications】Suitable for relative hardness testing of gemstones, cured epoxy concrete and other floors, ceramics, ceramic tiles, floor tiles, marble materials, ore geological exploration, optical glass, mobile phone glass screen tempered screens, and commonly used glass.