Many of the hollow agates of Brazil and Uruguay contain a crop of amethyst-crystals in the interior.
Garnets are plentiful in the Lindi district, and agates, topaz, moonstone and other precious stones are found in the colony.
The remaining mineral products include lead, from which a considerable quantity of silver is extracted, copper, cobalt, arsenic, the rarer metal cadmium, alum, brown coal, marble, and a few of the commoner precious stones, jaspers, agates and amethysts.
It is famous for the cutting and setting of agates and other precious stones, an industry which has been established here, and in the neighbouring township of Idar, since the 16th century.
All the spandrils of the Taj, all the angles and more important architectural details, are heightened by being inlaid with precious stones such as agates, bloodstones, jaspers and the like.
The diamonds of this district are noted for their purity and lustre, and are generally associated with other crystals - garnets, agates, quartz and chalcedonies.