This hardness pick set allows you to test the hardness of gems and minerals to aid in identification. Points are made of alloys equal to 2 through 9 on the Moh's hardness scale. Includes 4 double-ended picks with 8 points, glass hardness plate (5.5 hardness), second hardness plate (3.5 hardness), 100 grit sharpening stone, streak plate, magnet, 300-mineral hardness table, and complete instructions. Warning: Scratches to minerals will be permanent. Only use on test samples of minerals or inconspicuous areas.