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
EMLL 15th Anniversary Show debut of Blue Demon, who would later become one of the iconic figures of Mexican wrestling. The 1948 Anniversary show commemorated the 15th anniversary of the Mexican professional wrestling company "Empresa Mexicana de Lucha Libre" (Spanish for "Mexican Wrestling Promotion"; EMLL) holding their first show on September 22, 1933 by promoter and founder Salvador Lutteroth. EMLL was rebranded early in 1992 to become "Consejo Mundial de Lucha Libre" ("World Wrestling Council"; CMLL) signal their departure from the National Wrestling Alliance. With the sales of the Jim Crockett Promotions to Ted Turner in 1988 EMLL became the oldest, still-operating wrestling promotion