Marble is really a metamorphosed limestone, a carbonate of lime, with hardness of 3, specific gravity 2.71, and refractive indices 1.48-1.65. When pure, it is white in color, but it is more often streaked on account of included impurities, such as iron oxide. Nearly every color is quarried, and each variety is known by name according to the formation in which it occurs, its place of origin, or its peculiarity of color. Its structure is granular, and the interlocking grains of calcite, of which it is formed, may be easily seen if examined with a microscope. Although marble cannot be regarded as a gem stone, its beauty, comparative durability, and its low cost have enabled it to be used as a material by which the sculptor and the architect have expressed their ideas of beauty in consummate form. Both in Italy and in Greece, marble has been used as a medium by sculptors throughout many centuries. The buildings that still stand in Athens, such as the Parthenon, the Erecthelium and Propylaea, are composed of marble, as are also such outstanding works as the Hermes of Praxiteles and the Aphrodite of Melos. Many more modern buildings of outstanding beauty have been built of this material; for instance, nothing but marble was used in the building of Milan cathedral. There are a great many varieties of marbles; we shall mention a few as being of interest since they may be seen, either inside or outside many of the finest buildings existent. Cipollino was the first colored marble used in Rome, and in that city there are over five hundred columns of this marble alone today, including the portico of St. Peter's. The famous cathedral of St. Marks, Venice, is largely decorated internally with this stone. The pattern is distinguished by alternate bands of white and pale green mica, and its resemblance to the skins of an onion has given it its name. The quarries, originally worked by the Romans, were abandoned on the downfall of the Empire, and it was only after an intensive search that they were found in the last century. Piastraccia, quarried near Seravezza, is a white marble which is most suitable for statuary work. Carrara marble is similar in color, and this variety has been worked in Tuscany since Roman I times. It is famed internationally, for it has produced such buildings as the Leaning Tower of Pisa and the modern Marble Arch in London. Another marble, Verde Antico, greenish in color, was quarried in Thessaly some two thousand years ago, and the quarries, lost for 1,600 years, were re-discovered in 1886. Travertine, a hard wearing marble of a straw color, was a popular building stone in Rome from the Second Century B.C. onwards. The Colosseum was built of this stone, and its condition to-day testifies to the wearing qualities of this particular variety. Another Italian marble is Black and Gold. This beautiful species is a breccia, with a black body and golden veins stained by carbonate of iron. Rouge Languedoc is a red marble with white patches, and it is quarried in the Montagne Noire, near Carcassonne (France). It is the most popular of the French marbles, and its use is evident in many Italian and French churches, as well as in such buildings as the Louvre, Arc de Triomphe, and the Palace of St. Cloud. Botticino is quarried in Lombardy, and in color varies from a uniform dark brown to a light cream. This marble, being of compact texture and taking a good polish, is universally used, especially in statuary work. Breche Rose comes from Norway, and it is a beautiful pink stone with no veining. It has a coarse texture, and takes little polish. Roman Stones, of which there are many varieties, but all distinguished by shell-like markings, are quarried in Istria and near Rome. They have been much used in northern Italy (Ravenna) and in Austria. The facades of the Doge's Palace in Venice are of this stone. Siena Brocatelle is a rich yellow stone, quarried near Siena and distributed from the nearby port of Leghorn. Vert de Mede is a French Pyrenean hard marble; France also supplies Escalette, Campan Rose, both from the Pyrenees, where traces of Roman occupation are often found in the quarries, Jaune Lamartine from the Jura, and the Joinville series from the Vallee Heureuse near Boulogne, the last being of a brownish color and much used in England. Sweden produces a greenish marble, now extensively used for pavements and exterior work. Belgium exports a number of black marbles which are suitable for many purposes, and especially for shop fittings. In England, there are Devon and Derbyshire marbles. Greece, Portugal, and Algeria also produce good material, while India yields some foliated marbles of a fine tone and smoothness, but rather hard and yellowish. The beautiful green Landscape Marble, also called Ruin Marble and Cotham Marble, is a gray limestone found at Cotham, near Bristol, England. When slices are cut and polished, they present fanciful representations of landscapes and trees. The so-called Mexican onyx, Brazilian onyx, Algerian onyx, and Californian onyx, used in the form of ash trays and other smaller ornamental objects, are not onyx but varieties of marbles. The brown zones, separated by sharp lines, are due to the presence of iron oxide. The finest qualities are found in Algeria, Argentina, Mexico, Chile, Egypt, and the Pyrenees. This material is generally of a dull green or yellow color, often streaked with brown and red. Sometimes it is banded and irregularly colored. That of a greenish color, veined with red and yellow, is quarried near La Toma, in San Luis province, and at Los Tolditos (Mendoza province) in Argentina. Other beautiful marbles are quarried in the Cordoba hills, in San Juan and La Rioja. In Mexico, the material called tecali by the natives is a local marble, and it is carved into ornaments for local consumption. Certain limestone beds in the states of Puebla and Oaxaca, Mexico, produce this stone. Clock cases, figures, ash trays, lamp fittings, bases for bronze ornaments, and other objects which are sold in many countries have been cut mostly from French and Algerian stones. Such material, a massive calcite, carbonate of lime, may be easily distinguished from onyx and agate by its inferior hardness, which is only 3. It also effervesces when touched by an acid; true onyx is not affected. These are but a few of the many marbles used and classified. There are many others, all of which are suited for some purpose. The chief center of marble work in Europe is Italy, where the industry is of considerable importance. One sometimes encounters a reddish stone which may have been artificially stained pink or red, and which has been worked into beads to simulate coral. Such bead necklaces, generally of good size, originate from Italy or Japan, and they may be unsus-pectedly bought for coral in sales rooms or through second-hand channels. The material is really either an alabaster or a marble, but the coldness and relative weight should be sufficient to distinguish it from coral. Despite the many artificial materials which are now available, marble still holds its own as the most beautiful and enduring material for building purposes. To the ancient writers, it was known as lychnites, as the quarries in Greece were once worked by the light of lamps. The Greek word lukhnos signifies "a lamp." |
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Like alabaster, marble is an ornamental stone used chiefly in architectural and large decorative work. Some variety of marble is found in almost every country. Its uses are well known, but its properties are not so generally recognized.