In this magazine for August, 1927, S. C. Davidson gave a brief preliminary account of the geological relations of the hiddenite deposit. In the following pages are presented the results of the petrographic study of materials collected in 1926, made principally by Davidson but extended and verified by Goranson. To these have been added crystallographic data, in part based on Goran-son’s observations, in part on those of Mr. Berman and the senior author. The latter was able to study additional material through the kindness of Mr. B. S. Colburn of Asheville, N. C. This gentleman has assembled in a private museum at Asheville all the numerous specimens taken from the hiddnite mine when reopened in 1926 under the direction of his brother, W. B. Colburn. A careful examination of this interesting collection was made by Palache in 1930 and Mr. Colburn also supplied photographs of some of the matrix specimens of hiddenite and additional crystallographic material for study. We desire to express here our great indebtedness to the Messrs. Colburn for the many favors received at their hands.