Hurlbut, Cornellius S. (Cornelius Searle), 1906- Gemology / Cornelius S. Hulburt, George S. Switzer - New York : John Wiley & Sons, 1979 - 243 p. : il. ; l 25 cm. 'A Wiley-Interscience publication' Includes bibliographies ISBN: 047142224X Subjects--Topical Terms: Precious stones