Compared to older charts these give a more precise match to the actual observations in the modern optical microscope. As an example, interference color transitions on wedge shaped olivine grain boundaries toward epoxy, match accurately the interference color in the new charts.

The differences in the color between older charts and the new are most pronounced in the second order, where the saturated green is now replaced by greenish white and turquoise. In addition, the pinks are shown to cover a larger range than previously thought. The revised charts make it easier to determine interference color and order, and hence also to determine the birefringence of the common silicate minerals.

Because of the first principle origin of the charts it is easy to adjust the charts for different types of optics and illumination. Also with the improved understanding of interference color opens up new possibilities in image analysis of transmitted light images involving interference color.

Current work focusses on including the efects of absorbtion and dipsersion, giving rise to the anomaleous interference colors. This is still under devolopment, but preliminary results will be shown at the conference.

Sørensen, B.E. (accepted) "A revised Michel Lévy interference color chart based on first principles calculations" European Journal of Mineralogy