THE TECHNOLOGIST. 



THE MARBLES OF ITALY. 



BY IGINO COCCHI, 



Professor of Mineralogy and Geology in the Royal Museum of Natural History at 



Florence. 



The name of marble is restricted to certain limestones of a crystal 

 line or granular structure which are sufficiently compact to be suscepti- 

 ble of taking a high polish. 



As examples of the crystalline or saccharoidal structure, we may 

 take the white marbles of the Apuan Alps (Lunigiana, Carrara, Massa, 

 Seravezza, &c), the " Bardigli " of the same localities, those of Valdier, 

 in Piedmont, and certain of the marbles of Venetia, Trentino, and the 

 province of Brescia. 



If the crystallisation is of a very decided character, the structure be- 

 comes lamellar, as in the white marble of Pallanza, the Bardigli, and 

 statuary marbles of Monte Rombolo, Monte Calvi (Campiglia), and the 

 island of Elba, which are in every respect equal to the famous marbles 

 of Paros. 



The granular structure is seen in the white marbles of the Monte 

 Pisano, the yellow of Siena, or giallo di Siena, and the maj ority of the 

 marbles exhibited by the Neapolitan and Northern provinces. 



The black marbles of Spezzia, Brescia, &c, certain varieties of alberese 

 and the fine slates from Perugia, exhibited by Count Orini, furnish 

 examples of compact limestones of a very fine grained structure. 



These limestones mark the limit dividing the ornamental marbles 

 from those that are only fitted for building purposes. The price of the 

 former is more or less considerable, according to their varying capacity 

 for taking and retaining a fine polish, like that of black marble, a quality 

 which is not possessed by any other rock of the same colour. 



The breccias, or brecciated marbles, are formed of fragments of lime- 

 stones united by a more or less calcareous cement, or they may contain 



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