Reducing Confusion in Refractive Index Determination by Adapting the Chart from Figure 5-9 in Optical Crystallography by Bloss: A Technical Note
THE MICROSCOPE
2024, Volume 71:2, pp. 77–79
DOI
https://doi.org/10.59082/NZNM9078
AUTHOR
Wayne Moorehead
ABSTRACT
Identification of unknown particles using the immersion method with a polarized light microscope was taught in a tier one university forensic microscopy course using Optical Crystallography by F. Donald Bloss as the foundational text for understanding the theory of optical properties observed in the microscope. A chart from the text, Figure 5–9, was confusing to students. By inverting the chart, the students’ observations of optical properties appeared more consistent with the information contained in the chart. Thus, this revised, inverted chart is more useful toward determining the refractive index of an unknown particle. View or download a high-resolution PDF of the new chart, Figure 5-9 (adapted by Moorehead) from Bloss, Donald, (1999). Optical Crystallography, 40. Mineralogical Society of America: Figure 5-9 (adapted)