A DATABASE OF INDUSTRIAL MINERALS BASED ON OPTICAL PROPERTIES: A GUIDE TO THE MINERAL RESOURCES OF NORTH CAROLINA STATE UNIVERSITY’S MINERALS RESEARCH LAB

The North Carolina State University Minerals Research Laboratory is responsible for processing and evaluating industrial minerals for use in commerce and in industry. These industrial minerals are used in a wide range of applications from electronics and military grade weaponry to more common materials like ceramics, paints and glass. The quick and efficient identification of each mineral plays an important role in evaluating the ore. This project aims to aid in the identification of minerals by creating a database based on the optical properties of common industrial minerals.

Samples were ground to 105 microns and made into grain mounts for observation under the polarized light microscope (PLM). The polarized light microscope was used to identify main optical properties such as refractive index, retardation, optical class and optical sign. Additional optical properties such as extinction angle and 2V were also observed when applicable to help further classify each mineral. A variety of pictures is also included to exhibit each mineral in both plane and cross polarized light as well as give a visual display of Becke lines. Ultimately, the database will result in a full record of the Mineral Research Laboratory’s industrial mineral holdings. It will also allow those employed at the lab to easily and efficiently identify an unknown mineral by its’ optical properties.