Page:Vol 3 History of Mexico by H H Bancroft.djvu/607

Rh, Zacatecas, Jalisco, and other districts, and was worked for some time, but only to a limited extent. Still worse fared it with copper which abounded in Michoacan. Mines were leased at a low price in 1657 and attempts were made by several viceroys to work them, but they were invariably abandoned after a brief trial. The great abundance of precious metals seems to have excluded the others; all mining except for the precious metals was as a rule limited to local demand, and only in the nineteenth century has more attention been given to others, as will be shown in a later volume.

More prominent were the quarries of tetzontli, the porous amygdaloid found in the neighborhood of Mexico and so frequently used for its buildings. Salines were extensively worked in different parts of the country, chiefly in Jalisco, Peñon Blanco in San Luis Potosí, Colima, and Oajaca. As the produce was required not only for domestic purposes but for the amalgamation process, minute regulations appeared as early as August 23, 1580, concerning their management, and in later years they were temporarily reserved for the crown. The process of extraction consisted merely in distributing the salt water into shallow pools to be evaporated. Rock salt was not known.

From the frequent allusions of the early chroniclers an abundance of precious stones might be supposed to exist in New Spain, and in 1541 petitions were in fact directed to the king, soliciting permission to work deposits of sapphires, rubies, and turquoises in Oajaca. Nothing came of it, however, evidently because the