A punched card system has been developed for the identification of ore minerals, especially the fine intermixed and disseminated forms of most ores. The variation of chemical and physical properties introduces a sufficient number of possible permutations to warrant use of the identification aid. Details are given for the preparation of a set of determinative cards. A brief evaluation of certain determinative data has been attempted. The unreliability of so-called "tarnishing reactions" has been suggested.Several examples of the use of punched cards in the identification of unknown minerals are presented. Their possible application to published descriptive data is indicated.Two new mineral names are presented. A plea is made for the naming of distinctive microscopic minerals.