Getting acquainted with minerals George Letchworth English [and] David E. Jensen. English, George Letchworth, 1864-1944. Jensen, David E. (David Edward), joint author. Mineralogy. Mineralogy United States. QE365 .E5 1958 549 JEG New York : McGraw-Hill, 1958. 1958. 1958 Text 362 p. : eng United States.