SAPPHTEE IN UNITED STATES. 108 
A very common develo[)ment that Avas noticed on nearly all the flat 
rhombohedral crystals and on many of the prismatic crystals is a 
repeated growth on the basal })lane of the rhomboliedron r (1011) 
and the base c (0001), as represented in figs. \-(S of Pl. V. 
To illustrate better the variation in these growths, a series of draw- 
ings, figs. 9-14 of PI. V, have been made in basal projection. In figs. 
9 and 10 of PI. V, which represent the more common development of 
these repeated growths, there is but one secondary rhomboliedron 
and base, which sometimes has one of its rhomboliedron faces a con- 
tinuation of one of the rhomboliedron faces of the crystal. Figs. 11 
and 12 of PI. V 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 V, the basal 
plane of the crystal has the appearance of being striated with trian- 
gular markings when the secondary growths are but slightly devel- 
oped. In figs. 13 and 14 of PI. V is represented a series of growths 
where a number of the rhombohedral faces coincide. 
Some of the pyramidal crystals (figs. 7 and 8 of PI. V) 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 striations; some are 2 
mm. in thickness. A few crystals were observed on which there was 
a secondary growth parallel to the prism a (1120). This same style 
of development has been described by Bauer « as occurring in the 
Burma rubies. 
The sapphire crystals from Montana, described on page 100, are 
strikingly similar in this respect to the Co wee rubies. Among the 
most noticeable associated minerals of these Cowee rubies is the deli- 
cate rose-colored garnet, rhodolite, which has already been mentioned. 
It usually occurs in waterworn jiebbles, but it has also been found in 
very small dodecahedrons. The other accompanying minerals are: 
Quartz, rarel}^ as pseudomorphous dodecahedrons; corundum crys- 
tals, of pale blue, amethystine, and pink shades; spinel (pleonaste) ; 
gahnite, in octahedral crystals; chromite (rare) ; rutile; menaccanite; 
bronzite (transparent); tremolite; hornblende; iolite (colorless); 
cyanite; fibrolite; staurolite, in perfectly transparent fragments of a 
garnet-red color; monazite in small crystals; zircon, small brilliant 
crystals, and also the variety cyrtolite; pyrite; chalcopyrite; pyr- 
rhotite; sphalerite; sperrylite 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. 
" Loc. cit., p. 209. 
