There are but very few stones whose colors resemble that of the emerald, and therefore frauds are easily detected. A well-selected specimen of prase may be passed as an inferior emerald, as well as the translucent stones cut from the Chinese jade; but their want of transparency offers a serious objection to them as a gem. The green tourmaline, when it approaches the emerald in hue, is of equal value. The green zircon and the green spinel would be far superior to the emerald in brilliancy, and therefore of greater value to the amateur. The chrome-green garnet of Hungary and the emerald-green garnet of Siberia would command a high price, if of pure color, as they surpass the glucina emerald in eclat and are moreover exceedingly rare. The peridot may assume the exact hue of the Granada emerald. The glass imitations are almost _fac-similes_ in hue, and are far superior in brilliancy to the mineral itself; but their softness, which readily yields to the file, betrays their nature without difficulty. Since the time of the Spanish Conquest, New Granada has furnished the world with the most of its emeralds. The most famous mines are at Muzo, in the valley of Tunca, between the mountains of New Granada and Popayan, about seventy-five miles from Santa Fé de Bogota, where every rock, it is said, contains an emerald. At present the supply of emeralds is very limited, owing to restrictions on trade, and want of capital and energy in mining operations. Blue as well as green emeralds are found in the Cordillera of the Cubillan. The Esmeraldas mines in Equador are said to have been worked successfully at one period by the Jesuits. The Peruvians obtained many emeralds from the barren district of Atacama, and in the times of the Conquest there were quarries on the River of Emeralds near Barbacoas. Emeralds of a poor quality are found at Limoges in France, and also in Norway. In some of the felspar quarries in Finland they occur in large thick crystals, several feet in thickness, of a fine color, but not transparent.