482 REPORT ON NATIONAL MUSEUM, 1886. 



cement is very small, and the actual displacement of the various par- 

 ticles but slight. When cut and polished the slabs have somewhat the 

 appearance of mosaics, representing the ruins of ancient castles or 

 other structures. Hence the name of " ruin marble." The locality as 

 given by Delesse, is in the environs of Florence, Italy, at the bridge 

 of Eignaud, valley of the Siene. 



(8) JAPAN. 



Stone is but little used as yet in Japan for purposes of construction. 

 Granite, trachyte, and trachyte-tuff are said (o be used for foundations, 

 temple stairs, gate-ways, sea-walls, and battlements, but the super- 

 structures are nearly always of wood, this material being preferred on 

 account of its cheapness. * A variety of marbles and other stones, suit- 

 able for decorative purposes, are found in Mino and Hitachi provinces, 

 and quite a complete series of these have been received at the National 

 Museum. Those from Mino are white, reddish, blue gray, and nearly 

 black, with white fossils. They are often beautifully brecciated. One 

 of the finest varieties from Hitachi province has a, nearly white ground- 

 mass, traversed by a net- work of fine bluish lines like the Italian bar- 

 diglio. Other colors are pure white, white with greenish veins and 

 blotches, caused by a talcose mineral. There is also quite a series of 

 dark greenish, sometimes nearly black, rocks, variously spotted with 

 elongated crystals of black amphibole, and which are evidently steatite 

 or agalmatolite. They are catalogued merely as marbles, and as yet no 

 opportunity has arisen for an accurate determination of their mineral 

 composition. 



(9) MEXICO. 



Mexican onyx. — This beautiful stone, which, however, is not a true 

 onyx, but a travertine, occurs, according to M. Barcena,t in extensive 

 deposits in several localities in Mexico, but that at present most worked 

 is located in the neighborhood of Tecali, State of Puebla. As here 

 found, the rock is interstratified with " argillaceous calcareous rocks," 

 marls, and sands. It is of a fine even grain, close surface, and permits 

 of a very high polish. Its colors are varied ; green, red, amber, yellow, 

 through all shades to white, beautifully veined and mottled, are com- 

 mon. It is translucent, and the colorless varieties quite transparent 

 in slices not over one-fourth inch in thickness. I am informed by Sig- 

 nor Aguilera, of the Mexican Geological Commission that slabs 2 feet 

 jn diameter and one-fourth inch in thickness have been used as window- 

 panes in the building of the University of Mexico, and with beautiful 

 effect. The same gentleman also informs me that the ordinary varie- 

 ties of the stone are so common and little esteemed in the vicinity of 

 the quarries, that the rough blocks are utilized by the natives in build- 



* Official Catalogue, Japanese Section, Internat. Ex., Philadelphia, 1876. 

 t Proc. Acad. Nat. Sciences, 1876. 



