while other metals and mineral substances are almost neglected, although present in proportion. The volcano Popocatepetl is said to be one vast pile of sulphur. In every state there are quarries of white and colored marbles—those of Puebla especially remarkable for their rich veins of variegated colors, which, properly worked, would make beautiful decorative columns and other architectural ornaments. At present, the specimens of this "Puebla onyx" are limited to paper-weights, pen-handles, and other small articles, which, without any solid value, serve to show the variety and beauty of the material. Precious stones are not unknown in Mexico; opals, with fickle rainbow hues, now brilliant, now vanished, are found in many places, and counterfeited in many others. Turquoise, garnet, topaz, and amethyst are among the native jewels of the Mexican mines.
