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
Lead 15th Anniversary Live Box MCs. For "Lead 15th Anniversary Live ～Kan Ima Shirube-sai～", the group performed every a-side they had released since their debut in 2002, up until their then-most recent song "Beautiful Day", which had been released on August 23, 2017. The live was well-received, with people praising the group's stage presence and charisma, even with performing so many songs for one performance, many of which were dance tracks. "Lead Upturn 2017 ～This is Our Day～" was the group's fifteenth live tour. For the performance, most of the music utilized were songs from their seventh studio album "The Showcase", which had been released