Iolite and Herderite Optic Character
Iolite and Herderite optical properties play a significant role while distinguishing these gemstones from each other. These properties are influenced by the Iolite Vs Herderite 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 Iolite and Herderite 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.