MARBLE (OF. marble, marbre, Fr. inorbre, Prov. marine, marbre, from Lat. marble, from Gk. Acippapos, marmaros, bright stone, marble, from pappa(pecr, maromirein, to sparkle). In a strict sense a crystalline limestone having a granular structure. The term has, however, become broadened as a result of commercial use and now includes any limestone, either crystalline or non-crystalline, which will take a polish. Marbles vary considerably in their texture and color. Some are extremely fine-grained, like those of Vermont, while others are coarsely granular, as in New York State. Those com posed entirely of carbonate of lime are pure white, but many are colored gray or blue by car bonaceous matter, while others exhibit beautiful shades of pink, yellow, red, and brown, due to iron compounds. The presence of fossil remaims may also add to their beauty. Marbles are usually found in regions of metamorphic rocks I we GEOLOGY) , and hence the rock has been at times subjected to crushing forces. These have developed fissures in the rock, which subsequently became filled by foreign mineral matter, and it is to this that much of the beautiful marking or veining of many ornamental marbles is due.
Marble occurs in many geological formations, but in the Unitr.d States it is obtained mostly from the Paleozoic rocks. The best-known de posits are found in the Eastern States. In west ern Vermont, at West Rutland, Proctor, Bran don, and other localities, some of the quarries have reached a. depth of 400 feet. and contain many grades, varying from the purest white statuary marble to the gray, or 'true blue' variety, as it is called. Vermont supplies SO per cent, of the marble used for monumental work in the United States. A fine-grained, white, dolomitic marble is quarried at Lee, in western Massachusetts, and also near Pittsfield. Much marble for structural work is obtained from Saint Lawrence and Westchester counties. N. V.; from Coekeysville, Md., and Pickens County, Ga. These
are all magnesian marbles of coarsely crystalline character. Black marble was at one time quar ried near Glens Falls, N. Y.; and at Swanton, Vt., there occurs a deposit of variegated marble much used for wainscoting and floors. Some of the varieties found here resemble imported marbles. About 60 per vent. of the marble used in the United States for furniture tops and in terior decoration is obtained from near Knox ville, Tenn. The colors are variegated, but chiefly veinings and mottlings in red, brown, pink, and gray. Aside from these areas, marble of white and gray striping is quarried in Ingo County, Cal. Two types which have attracted some attention arc the serpentine or verde an tiques found in eastern Pennsylvania. and the onyx marbles from Arizona, Colorado, and Cali fornia. These latter are not true onyx. but a. travertine, eomnosed of carbonate of lime, and formed in eaves or around calcareous springs.
Many ornamental marbles are imported into the United States from various European coun tries. Among the more important types are: Black and Gold, a black Italian limestone veined with yellow; Broratelle, a light yellow marble with red elondings, obtained from the Pyrenees; Carrara. the white marbles quarried at Carrara, Italy; Giallo antic°, a yellow marble much sought after by the ancient ;reeks and Romans; and (;riot/c, a bright red variety, obtained in the Pyrenees. The last named is also found it Swanton, Vt. Landscape marble is a variety con taining coloring matter dispersed through it in such a manner as to resemble a landscape. Ntro antico is a greenish-black serpentine marble; Numidian marble is an African variety, often of yellow color; Varian, a white marble much used by the ancient Greeks and obtained from the island of faros; Pentcliie is another white marble used by the ancient Greeks, occurring near Athens; /eos.so ontico, a red marble; Nina, a yellowish marble, often with veins or patches of gray or purple.