This gemological tool is helpful for identifying certain red, blue and green gemstones.It is used to determine whether a gemstones is natural or synthetic.Can also be used for detecting Synthetic Blue-Spinel and for detecting dyes in certain gemstones. Most popular and easy-tool for identification. Small size, portable, easy to carry. Colour:As Shown Material:Metal Package Contents: 1 * Filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin