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
Gift shop differentiation. Many shops that are not primarily gift shops become gift shops during typical gift-giving periods such as Christmas and Valentine's Day, offering ranges of gift products for a limited time period in the build-up to these celebrations. Online gift shops are websites which have the primary objective of selling products online that will be given to others. These online retailers may or may not be associated to a physical shop. Gift shop A gift shop or souvenir gift shop is a store primarily selling souvenirs relating to a particular topic or theme. The items sold often include coffee mugs,