Polariscope is an instrument used in gemmology which helps to find if the gemstone is single refractive or double refractive and also allows determining the various crystal axis of the stone. ... A polariscope is made of two Polaroid plates that rotate, a power switch, a stone holder and a bottom light source.
1-
DR is Anisotropic = double refraction means (DR)
SR is Isotropic = single refractive =single colour mean (SR)
2-
7 out of 6 CRYSTALLINE is DR
CRYSTALLINE Cubic System are SR
Pollycrystalline Or Microcrystalline Gemstones do not blink and stay light during 360 degree
3-
POLLYCRYSTALLINE GEMS Stone stays Light through 360 rotaion in all orientaions.
