... absorption line for the impurities existenceZooming check: strong birefringence,cleavageSpecial optical effect: Cat's eyeOptimization process: -Dyeing:dyed into different ... the appearance,surface shows Greasy luster,,easy colliquable,it can test with probe tip-Irradiation: to show blue,yellow and ... will fade away,avoid heating and exposureing.hard to test Calcite powder used in man-made stone, man-made ...