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
Chinese pre-wedding customs food, such as peanuts and dates (in Chinese, the word for "date" is a near homonym of "early", while "peanut" is "birth"). This is normally presented on the wedding day, with the wishes of giving birth to a child early in the marriage. Candles and paper cut "Double Happiness" are often seen on a wedding day as well. The bride price, which is given by the groom's family to the bride's family, varies from region to region. In Southern China, the bride price is much higher than in Northern China. After the betrothal gifts and bride price are negotiated and