Gemological characterization of flourite from Kamar Mehdi mine in Tabas and its comparison with Qarava mine in Saqez

Most of fluorite mines in Iran were formed in the Triassic limestones. The Kamar-Mehdi fluorite mine located in the SE of Tabas and Qarava fluorite mine in SE of Saqqez, respectively. Following the field observation, samples were selected according to the colors and transparency. Samples of Qarava mine is blue and Kamar Mahdi are purple, low pink and low green. Sample luster of the two mines are vitreous with spelendent intensity. All samples from two mines show fluorescence characteristion and aggregate (Agg) optical properties. The reflective index rate of Qarava and Kamar Mahdi samples are 1.43 and 1.42- 1.44, respectively. Kamar-Mehdi clarity grading samples are HI (Highly included), while samples Qarava is clarity grading SI (Sightly included) to HI (Highly included). Also Qarava fluorites are transparency and clarity grading higher gem quality. Because of fluorite sensitivity to heat and its low hardness, several different ways were tested to find the best cutting process and cutting tools. With respect to our lab experiences, using the 0.3 mm cutting blade in the cut step, 240 mesh disk abrasion, 360 mesh polisher to scratch-making and 900, 2000 and 5000 mesh polishers for polishing are the best tools in Cabochon and Fantasy cutting of flourite.