Emerald says: "§ 23.23(c) It is unfair or deceptive to use the word "laboratory-grown", "laboratory-created", "[manufacturer name]-created", or "synthetic" with the name of any natural stone to describe any industry product unless such industry product has essentially the same optical, physical, and chemical properties as the stone named." Emerald is regarded as the traditional birthstone for May as well as the traditional gemstone for the astrological signs of Cancer. One of the quainter anecdotes about emeralds was told by the 16th-century historian Brantôme, who referred to the many impressive emeralds the Spanish under Cortez had brought back to Europe from Latin
Western Mexico shaft tomb tradition This circular architectural style is seemingly mirrored in the many circular shaft tomb tableau scenes. Known primarily from this architecture, the Teuchitlán tradition rises at roughly the same time as the shaft tomb tradition, 300 BCE, but lasts until 900 CE, many centuries after the end of the shaft tomb tradition. The Teuchitlán tradition appears to be an outgrowth and elaboration of the shaft tomb tradition. Because western Mexico is on the very periphery of Mesoamerica, it has long been considered outside the Mesoamerican mainstream and the cultures at this time appear to be particularly insulated from many mainstream Mesoamerican