44 CORUNDUM IN THE UNITED STATES. [bull. 180. 
repeated growth on the basal plane of the rhombohedron r (loll) and 
the base c (0001), as represented in figs. 1-6 of PL III. 
To illustrate better the variation in these growths, a series of 
drawings, figs. 0-14 of PL III, have been made in basal projection. 
.In figs. 9 and 10 of PL III, which represent the more common develop- 
ment of these repeated growths, there is but one secondary rhombo- 
hedron and base, which sometimes has one of its rhombohedron faces 
a continuation of one of the rhombohedron faces of the crystal. 
Figs. 11 and 12 of PL III represent the repeated growths, the faces of 
which are separate and distinct from one another and from the faces 
of the main crystal. In the crystals represented by fig. 12 of PL III, 
the basal plane of the crystal has the appearance of being striated 
with triangular markings when the secondary growths are but slightly 
developed. In figs. 13 and 14 of PL III is represented a series of 
growths where a number of the rhombohedron faces coincide. 
Some of the pyramidal crystals (figs. 7 and 8 of PL III) also show 
the development of the secondary growth of rhombohedron and base. 
The thickness of the rhombohedron of the secondary growth varies 
greatly: some are so thin that they appear like striatums; some are 2 
mm. in thickness. A few crystals were observed on which there was 
a secondary growth parallel to the prism 1120. This same style of 
development has been described by Bauer 1 as occurring in the Burma 
rubies. 
The sapphire crystals from Montana, described on page 53, are 
strikingly similar in this respect to the Cowee rubies. Among the 
most noticeable associated minerals of these Cowee rubies is a delicate 
rose-colored garnet of great brilliancy, to which the name rhodolite 2 
has been given. The rhodolite usually occurs in waterworn pebbles, 
but it has been found in very small dodecahedrons, and its close con- 
nection with the rubies in the small crystals of rhodolite inclosed by 
the garnet has already been mentioned. 
The other accompanying minerals are: Quartz, rarely as pseudomor- 
phous dodecahedrons; corundum crystals, of pale-blue, amethystine, 
and pink shades; spinel (pleonaste); gahnite, in octahedral crystals; 
chromite (rare) ; rutile; menaccanite; bronzite (transparent) ; tremo- 
lite; hornblende; iolite (colorless) ; cyanite; fibrolite; staurolite in per- 
fectly transparent fragments of a garnet-red color; monazite in small 
crystals; zircon, small, brilliant crystals, and also trie variety cyrto- 
lite; pyrite; chalcopyrite ; pyrrhotite; sphalerite; sperry lite in minute 
crystals; and gold. 
Much of the work that has been done in Cowee Valley has been in 
the nature of prospecting to locate the extent of the ruby-bearing 
gravel and if possible to locate the origin of the rubies themselves. 
No work was done in the valley during the past year, but it is stated 
1 Loc. cit., p. 309. 
2 Am. Jour. Sri., 4 th series, Vol. V, L898, p. 294. 
