Tin pest related problems such as tin whiskers. At 13.2 °C (about 56 °F) and below, pure tin transforms from the silvery, ductile metallic allotrope of β-form "white tin" to the brittle, nonmetallic, α-form "grey tin" with a diamond cubic structure. The transformation is slow to initiate due to a high activation energy but the presence of germanium (or crystal structures of similar form and size) or very low temperatures of roughly −30 °C aids the initiation. There is also a large volume increase of about 27% associated with the phase change to the nonmetallic low temperature allotrope. This frequently makes tin
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