412 REPORT ON NATIONAL MUSEUM, 188fi. 



part of these granites : United States Mint, new City Hall, new Stock 

 Exchange, the Eeal Estate Associates' building, and several private 

 residences, and many monuments 5 all in San Francisco. 



A fine-grained very light-gray granite of excellent appearance is 

 found on the line of the California Southern Eailroad between Los 

 Angeles and Cucamonga, and is beginning to be used in Los Augeles. 

 In texture it is as fine as the finest Westerly, R. I., or Manchester, Va., 

 stone, and of a uniform light gray color. A coarser stone, carrying 

 abundant hornblende and black mica, is found also at Sawpit Canon, 

 in the same county. It works readily, but contains too much horn- 

 blende, and also too many small crystals of sphene, to be of value 

 for fine monumental work. 



Colorado. — Granites are at present but little worked in Colorado, al- 

 though the State contains great quantities of this material. A coarse 

 red granite has been quarried to some extent from bowlders at Platte 

 Canon, Jefferson County, but the rock is poor in color arid possesses but 

 little tenacity. Fine gray granite of good quality occurs at Georgetown 

 and Lawson, in Clear Creek County, and there are inexhaustible quan- 

 tities of equally good material all through the mountains, but which 

 are not quarried owing to the cost of transportation. A full series of 

 them is in the Museum collection. 



Connecticut — " Extensive quarries of granite and gneiss are located 

 at various points in this State, especially near Thomaston and Eoxbury, 

 in Litchfield County, on Long Island Sound, Fairfield County, near 

 Ansonia, Bradford, and Stony Creek, New Haven County, Haddam, 

 Middlesex County, and near Lyme, Man tic, Groton, and Mason's Island, 

 New London County. The Connecticut granites and gneisses are usu- 

 ally fine-grained and light gray in color, and the appearance is usually 

 so characteristic as to distinguished them from other granites of the 

 Atlantic States."* 



The most of these stones are, however, quarried only for local use, 

 and but few find their way into markets outside of the State. A beauti- 

 ful light gray muscovite-biotite granite is quarried at Thomaston and 

 Reynolds Bridge, which for evenness of grain and clearness of color 

 can not be excelled. The stone from Eoxbury is a tritle darker, but 

 though of fine and even grain and acquiring a good polish, is used only 

 for curbings, foundations, and pavings. The Ansonia rock is a very 

 fine-grained muscovite-biotite gneiss, and has been used for general 

 building purposes in New Haven and Bridgeport. The Leetes Island 

 and Stoney Creek rocks are of a pink color, the first mentioned being 

 sometimes very coarsely porphyritic. A turned column of the Leetes 

 Island rock in the Museum shows large pink orthoclase crystals 2 inches 

 or more in length embedded in the finer gray groundmass of the rock. 

 A beautiful and very coarsely crystalline red granite occurs near Lyme, 

 but for some unexplained reason the stone is not in the market. It has 



"Report Tenth Census, Vol. x, p. 127. 



