154 
MR. C. BARRINGTON BROWN AND PROFESSOR J. W. JUDD 
In the district of Mramorsk, near Ekaterinburg, in the Ural Mountains, corundum 
and emery are described by Gustav Rose as occurring in serpentine and chlorite- 
schist in association with cliaspore and zoisite.'" In the Ilmen Mountains, not far 
from Miask, and in the gold-washings north-east of Zlatousk, Kokscharow has 
described corundum as being found embedded in anorthite (“ barsowite”}.+ 
A very valuable contribution to our knowledge of the mode of occurrence of, and 
the minerals associated with, corundum is contained in the series of papers by 
Dr. J. Lawrence Smith on the emery formation of Asia Minor.| This author 
shows that the emery of the district in question is a blue corundum, mixed with 
magnetite, and that it is found, often in masses of considerable size, distributed 
through a crystalline limestone, which is interfoliated with schists and gneisses. The 
minerals which accompany the emery, or impure corundum, are cliaspore (common), 
hydrargillite (rare), zinc-spinel (gahnite), pholerite, margarite, muscovite, chloritoid, 
schorl, chlorite, magnetite, hematite, limonite, pyrite, rutile, ilmenite, and titano- 
ferrite. The localities at which the emery occurs are Gumuch-dagh, Kulah, Aclula, 
and Mauser in Asia Minor, and the neighbouring islands of Naxos, Samos, and 
Nicaria, in the Grecian Archipelago. More recently, Tschermak has given a fuller 
account of the emery of Asia Minor, and has shown what an important constituent 
of this rock is the mineral tourmaline.§ 
Corundum, in smaller quantities, is known to occur as a constituent of granite and 
gneiss in the Riesengebirge, Silesia, Auvergne, &c. ; in a compact felspar rock, at 
Mozzo, in Piedmont; in dolomite, with tourmaline, at St. Gothard ; while at Orange 
County, N.Y., and Sussex County, N.J., and other places, corundum has been found 
with a great variety of minerals in a crystalline limestone. 
Corundum has also been detected in masses of gneiss, &c., ejected from volcanoes, as 
at Konigswinter and Niedermendig, &c., and more rarely in the zones formed by 
contact metamorphism. It has also been detected in the metallic iron of terrestrial 
origin from Ovifak, Greenland. 
It is not necessary to discuss in this place the numerous occurrences of the mineral 
in its various forms, in river gravels and alluvia, and the various washings from which 
gold, platinum, and diamonds are obtained. 
Upper Burma has long been known to be the source of the magnificent red corundum 
(“pigeon’s blood ruby”), and also of the red spinels (Balas ruby), and of the pink 
tourmaline (rubellite), a gem which, by the Chinese, is prized even more highly than 
the true ruby. By Europeans the true, or oriental ruby, is regarded as not only more 
* ‘ Mineralogisch-geognostische Reise naeh dem Ural, dem Altai nnd dem Kaspisclien Meere’ (1837 to 
1842). 
t ‘ Materialien zur Mineralogie Russlands,’ vol. 1, p. 30; vol. 2, p. 80. 
+ ‘Am. Journ. Sc.,’ 2nd series, vol. 7 (1849), p. 283; vol. 9 (1850), p. 289; vol. 10 (1850), p. 354; 
and -vol. 11 (1851), p. 53. 
§ “Ueber den Smirgel von Naxos,” von G. Tschermak, ‘ Min. u. Pet. Mittli.,’ Bd. 14 (1894), p. 311. 
