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
Tin-Tin Kyrano that stereotypes are common but "handled with some sensitivity – all except for Tin-Tin, a literal China doll". Kate Hunt of the University of Glasgow, author of a study of the series' presentation of tobacco smoking, observes that in marked contrast with prolific smokers such as Penelope, Tin-Tin is "incongruously" and "inconsistently" seen with a cigarette in only one episode ("The End of the Road"). She writes that the character occupies a socially-ambiguous position within her home environment, appearing variously as "adopted daughter, secretary, and occasional member of the International Rescue team". In the 2004 live-action film, "Thunderbirds", in which