Polyhalite and Yttrium Aluminium Garnet Optic Character
Polyhalite and Yttrium Aluminium Garnet optical properties play a significant role while distinguishing these gemstones from each other. These properties are influenced by the Polyhalite Vs Yttrium Aluminium Garnet like crystallographic symmetry, pleochroism,etc. in the crystal. Some of the optical properties are refractive index, luster, optic character, pleochroism etc. Prominent among these is Polyhalite and Yttrium Aluminium Garnet optic character. You might have noticed your gemologist rotating the gemstone while testing it. Rotating a gemstone along its optic axis helps in determining its optic character.