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
Christmas gift (exclamation) also in southern Pennsylvania, Ohio Valley, West Virginia, and later in northeastern Texas as a simple greeting and recognizing the birth of Christ as a gift. A variant of the tradition is "Christmas Eve gift". The tradition is similar to the "Christmas gift" tradition, but occurs on Christmas Eve. The person being told "Christmas Eve gift!" is expected to present the person saying it to them with a small present, traditionally candy or nuts. The Dictionary of American Regional English traces the first written uses of this version to 1954. Christmas gift (exclamation) "Christmas gift" is an exclamation traced back