Crystal structure "white tin" respectively. Two more allotropes, γ and σ, exist at temperatures above 161 °C and pressures above several GPa. White tin is metallic, and is the stable crystalline form at or above room temperature. Below 13.2 °C, tin exists in the gray form, which has a diamond cubic crystal structure, similar to diamond, silicon or germanium. Gray tin has no metallic properties at all, is a dull gray powdery material, and has few uses, other than a few specialized semiconductor applications. Although the α–β transformation temperature of tin is nominally 13.2 °C, impurities (e.g. Al, Zn, etc.) lower the
Arena Naucalpan 15th Anniversary Show Arena Naucalpan 15th Anniversary Show The Arena Naucalpan 15th Anniversary Show was a major annual professional wrestling event produced and scripted by "Promociones Moreno" in conjunction with the professional wrestling promotion Consejo Mundial de Lucha Libre (CMLL), which took place on December 16, 1992 in Arena Naucalpan, Naucalpan, State of Mexico, Mexico. As the name implies the show celebrated the 15th Anniversary of the construction of Arena Naucalpan, "Promociones Morenos" main venue, in 1977. In 1996 "Promociones Moreno" became International Wrestling Revolution Group (IWRG), maintaining the annual Arena Naucalpan Anniversary tradition. The show became IWRG's longest running show and is