158 CORUNDUM, ITS OCCURRENCE AND DISTRIBUTION. 
Zirkel " mentions the occurrence of cornndnni as an accessory min- 
eral in the amphibolites of northwestern Austrian Silesia ; in the 
chlorite-schist of Nizhne-Issetsk, in the Urals; as a contact product 
of the diorites of Klausen, in Tyrol; in the andesite and tonalite of 
the Eifel; in a contact product of quartz-mica-diorite on quartz- 
2:)hyllite in Val Moja, and similarly in the kersantite of Michaelstein, 
Harz ; also in the graphite of Miihldorf , near Spitz, in lower Austria. 
In describing' the geology of the district around Pretoria, South 
Africa, Molengraaf ^ states that the oldest rocks of the region are 
granites and crystalline schists. Above these are another series of 
schist formations, comprising quartzites, clay slates, corundum 
schists, porphyroids, and chiastolite-schists that are cut by diabase 
dikes. He states that the corundum i)orphyroid resembles a feldspar 
porphyry, and that the corundum occurs in large individuals in a 
groundmass of (piartz and chlorite. From the description given, 
there is a possibility that there is corundum in quantity in this 
district. 
Pirsson ^* mentions the occurrence of corundum in small blue sap- 
phires in the fresh basalt of Unkel on the Rhine and Steinheim, near 
Frankfort on the Main. 
Morozewicz ^^ has described the occurrences of corundum in Russia, 
the chief of Avliich is in a rock composed essentially of anorthite and: 
corundum, together Avith spinel and biotite. He claims that this is at 
new^ type of alumino-silicate rock and calls it " kyschtymite." Otherr 
rocks in the Urals that contain corundum are made up almost exclu- 
sively of this mineral and orthoclase ; some of these are coarse grained, 
while others are fine. The coarse ones have been called corundum- 
pegmatite and the finer ones corundum-syenite. These rocks occur 
as dikes cutting through gneiss. It may be that when these corun- 
dum-bearing rocks of the Urals have been more specially examined 
as to their economic value they will be found to contain enough 
corundum to make them of importance as an ore of this mineral. 
In many parts of the western Yunnan district, China, as in the 
prefecture of Shunning Fu, sapphire, ruby, and emerald corundum, 
are said to occur.' 
" Lehrbuch der Petrogi-aphie, Leipsic, 1803, p. 461. 
" Neues Jahrbuch fiii- Mineral., vol, 9, 1894-95, pp. 174-291 ; and Am. Naturalist, 1895, 
p. 470. 
*■ Am. Jour. Sci., 4th ser., vol. 4, 1897, p. 422. 
" Tschermaks mineral, und pet. Mittbeil., vol. 18, pt. 1 ; and Kept. Bureau of Mines, 
Toronto, vol. 8, pt. 2. 1899, p. 285. 
^ U. S. Cons. Repts., Jan. 1900, vol. 72, No. 282, p. 95 ; reprinted from Mesny's Chinese' 
Miscellany, published at Shanghai, China. 
