XVlll OBITUARY NOTICES. 



ings. In the spring of 1871, he had exhibited to the Society 

 several peculiar crystals of corundum, altered either wholly or 

 partly into other mineral species. "Further chemical investiga- 

 tion of these crystals, and of others similar to them, gave results 

 leading to conclusions which seemed to possess interest not only 

 for the chemist and mineralogist, but in connection with their 

 paragenesis, to the geologist also." The largest deposits of corun- 

 dum in the world are in a chromiferous serpentine or chrysolite 

 formation and in the rocks adjoining thereto. Localities of this 

 mineral have been developed all the way from Massachusetts to 

 Alabama, and it will always be an interesting question by what 

 agencies such enormous quantities of alumina could have been 

 precipitated to form it. Especially so, since by its subsequent 

 alteration it has given rise to many of the most widely distributed 

 minerals and rocks. The most important deposit of corundum in 

 the East is that at Chester, Mass., discovered by C. T. Jackson, and 

 described mineralogically by C. U. Shepard and J. L. Smith. It 

 consists of crystalline corundum contained in a fine scaly chlorite, 

 and of a peculiar mixture of granular and crystallized corundum 

 and magnetite. By far the largest deposits of corundum, however, 

 occur in North Carolina, the corundum belt stretching south- 

 westerly from Madison county, N. C, through Georgia into Talla- 

 poosa county, Ala., a distance of at least two hundred and fifty 

 miles. The first large mass of corundum was found in 1847 on 

 the French Broad river, near Marshall. It was dark-blue in color 

 and was associated with chlorite and margarite. The outcrop of 

 the Culsagee mine, near Franklin, extends over thirty acres ; that 

 of the Cullakenee mine, about twenty miles southwest of this, ex- 

 tends over an area of three hundred acres. The corundum here 

 is generally of a grayish-white or pale ash-gray color, with specks 

 of sapphire occasionally. Sometimes, however, it is of a beautiful 

 pink color, associated with andesite, zoisite, margarite, hornblende, 

 and rarely with chlorite, spinel and tourmaline. Near Gainesville, 

 Ga., corundum exists as a nucleus in irregular kidney-shaped 

 masses of margarite or with a peculiar earthy mineral between 

 isabel and flesh-red in color, intersected at intervals by veins of a 

 fine scaly or massive margarite. • 



After this general survey of the geological conditions attending 

 the occurrence of corundum, Dr. Genth proceeds to discuss the 

 minerals which are associated with it. Corundum altered into 



