| [var. Chalcedony] Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 317. Blake, Wm. P. (1866), Annotated catalogue of the principal mineral species hitherto recognized n California and the adjoining states and territories being a report of the California State Board of Agriculture. 31 pp., Sacramento: 9 |