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
ROH 15th Anniversary Show of Honor Wrestling". Wrestlers portrayed heroes (faces) or villains (heels) as they followed a series of events that built tension and culminated in a wrestling match or series of matches. ROH 15th Anniversary Show ROH 15th Anniversary was the two-night 15th ROH Anniversary Show professional wrestling pay-per-view (PPV) event produced by the American wrestling promotion Ring of Honor. It took place on March 10 and 11, 2017, at the Sam's Town Live in the Las Vegas suburb of Sunrise Manor, Nevada. The first night was a pay-per-view broadcast, while the following night was a set of tapings for the ROH