Area of opals and chalcedonies

Abstract

Recently, we identified some opals that show the same appearance but different refractive index and spectrum wavelength of infrared spectrum.

These days, we receive many orders to identify opals neighboring chalcedonies and it is questioned to basic analyses such as refractive index.

Beside basic analyses, we additionally tried the microscopic infrared spectroscope, the Raman spectroscope, and checking the Vickers hardness to reach the clear identification of opals and chalcedonies.