Paragenesis of the mineral assemblage at Crestmore, Riverside County, California

Abstract

For more than twenty years the Crestmore locality has excited the interest of mineralogists. This interest was first aroused when specimens of blue calcite with monticellite and xanthophyllite were sent to A. S. Eakle. The first publication appeared in 1914 and since then numerous papers have been published on the mineralogy of Crestmore by A. S. Eakle, W. F. Foshag, A. F. Rogers, and others. Crestmore is situated on the extreme eastern lobe of the Jurupa Mountains about three miles west of Riverside, California. The Jurupa Mountains are an east-west range roughly eight miles long and three miles wide which parallels the front of the San Gabriel Mountains. The cement plant, limestone quarries, and mine of the Riverside Cement Company are located at Crestmore. Quarrying operations were started some seventeen years ago. The rocks were at first used as road metal, burned lime for sugar refining, and for the manufacture of cement. With the increased demand for cement the quarrying operations were given over entirely to that purpose. At the present time the material is obtained by underground mining.