Traditional metal working in Mexico one in silver, which represented the sun and moon respectively. The existence of gold and silver in Mexico was one of the main attractions for the Spanish in the New World, with the conquest of the Aztec Empire and subsequent exploration with the aim of finding more of these precious metals. Mining and metal working became a main aspect of the economy of colonial Mexico. Most of the emphasis was on the mining of gold, silver, copper, iron, lead, platinum and tin with much of the metal, especially gold, shipped to Spain. Initially, the working of metals in the new
Ceramic discharge metal-halide lamp discharge is contained in a ceramic tube, usually made of sintered alumina, similar to what has been used in the high pressure sodium lamp. During operation, the temperature of this ceramic tube can exceed 1200 kelvins. The ceramic tube is filled with mercury, argon and metal-halide salts (for example, sodium iodide). Because of the high wall temperature, the metal halide salts are partly vaporized. Inside the hot plasma, these salts are dissociated into metallic atoms and iodine. The metallic atoms are the main source of light in these lamps, creating a bluish light that is close to daylight with a