REVIEWS 
Mineralogy. By Kraus and Hunt. McGraw-Hill, 1920. Pp. 
xiv+ 561. $4.50. 
This is in many respects an excellent text, and one that should have 
wide use. The matter is presented in a simple, direct style and, while ~ 
abbreviated, is concise and to the point, and should be suitable for 
classes in first-year mineralogy. The presence of a moderate number 
of small photographs of distinguished mineralogists together with 
extremely brief histories is a feature of the book. 
Ninety-four pages are devoted to crystallography, thirteen classes 
being described in detail. This matter is taken largely from the senior 
author’s excellent Essentials of Crystallography (1906), and needs no com- 
ment here. As in the earlier work, no photographs of crystals are to be 
found in the part on crystallography. Instead the authors have included 
numerous photographs of crystal models. This makes the shapes of ideal 
crystals clear, but as most crystals found in nature are mote or less imper- 
fect, some photographs of crystals would have been of value. Under 
descriptive mineralogy there are numerous photographs of crystals. 
One hundred forty-three pages are devoted to the description of 150 
minerals. Although largely taken from the senior author’s Descriptive 
Mineralogy (1911), the material is abbreviated and is illustrated by 
numerous well-selected photographs. The arrangement of the minerals 
is strictly chemical, the authors even going so far as to put several 
minerals generally grouped with the oxides into separate divisions such 
as aluminates, ferrites, manganites, and titanates, and, vice versa, zir- 
con is placed with the oxides. Brucite, prehnite, vivianitey and wad 
are omitted. Varieties, occurrence, associations, important localities, 
and uses, as well as the more commonly described features of minerals, 
are given. 
The determinative tables for 150 minerals take 169 pages. They 
are based on physical differences—luster, color, streak, and hardness. 
One column in the tables describes the mineral associations. Color 
seems overemphasized, since it is in general less diagnostic than streak 
or hardness. As an illustration of this point, ten minerals with a wide 
range of color were selected, and of these brown biotite, red, yellow, or 
188 
