Colemanite pseudomorphous after inyoite from Death Valley, California

The frontispiece of this number is a photograph of an interesting specimen presented to the geology department of Stanford University by the late Mr. C. A. Waring of the California State Mining Bureau. This, and a similar specimen in the department museum collected by Mr. H. P. Knight, are from the Biddy McCarty mine of the Pacific Coast Borax Company in Death Valley, Inyo County, California. The specimen shown in the photograph was labeled in the field “colemanite after calcite,” while the other specimen was labeled “rare form of calcium borate.”