Abstract
With the perfecting of the immersion method for measuring the refractive indices of crystals, other means of mineral identification have been more or less relegated to the background, but their existence should not be forgotten entirely, for problems occasionally arise which they may aid in solving. Several years ago I published1 a comprehensive study of the absorption spectra of minerals, as seen with the microspectroscope. That paper has long been out of print, but every now and then requests for certain information along this line are received, so the republication of part of the data included in it, together with some obtained from other sources, seems worth while. The method of presentation adopted is directed toward the identification of transparent or translucent, more or less distinctly colored, minerals.
