Mesoamerica
Main article: Jade use in Mesoamerica
Jadeite pectoral from the MayanClassic period (195 mm or 7.7 in high)
Jade was a rare and valued material in pre-Columbian Mesoamerica. The only source from which the various indigenous cultures, such as the Olmec and Maya, could obtain jade was located in the Motagua River valley in Guatemala. Jade was largely an elite good, and was usually carved in various ways, whether serving as a medium upon which hieroglyphs were inscribed, or shaped into symbolic figurines. Generally, the material was highly symbolic, and it was often employed in the performance of ideological practices and rituals.
Enhancement
Jade may be enhanced (sometimes called "stabilized"). Note that some merchants will refer to these as grades, but it is important to bear in mind that degree of enhancement is different from colour and texture quality. In other words, Type A jadeite is not enhanced but can have poor colour and texture. There are three main methods of enhancement, sometimes referred to as the ABC Treatment System:
• Type A jadeite has not been treated in any way except surface waxing.
• Type B treatment involves exposing a promising but stained piece of jadeite to chemical bleaches and/or acids and impregnating it with a clear polymer resin. This results in a significant improvement of transparency and colour of the material. Currently, infrared spectroscopy is the most accurate test for the detection of polymer in jadeite.
• Type C jade has been artificially stained or dyed. The effects are somewhat uncontrollable and may result in a dull brown. In any case, translucency is usually lost.
• B+C jade is a combination of B and C: it has been both impregnated and artificially stained.
• Type D jade refers to a composite stone such as a doublet comprising a jade top with a plastic backing.