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
Wedding Typically, this ceremony is held to commemorate a milestone wedding anniversary. It may also be held to recreate the marriage ceremony in the presence of family and friends, especially in the case of an earlier elopement. A same-sex wedding is a ceremony in which two people of the same sex are married. This event may be legally documented as a marriage or another legally recognized partnership such as a civil union. Where such partnerships are not legally recognized, the wedding may be a religious or symbolic ceremony designed to provide an opportunity to make the same public declarations and celebration