White tin, having a body-centered tetragonal crystal structure at room temperature,transforms,at 13.2
The rate at which this change takes place is extremely slow; however, the temperature (below 13.2 องศา) the faster the rate. Accompanying this white tin-to-gray tin transformation is an increase in volume (27 percent),)and,accordingly,a decrease in density (from 7.3 g/cm to 5.77 g/cm).
consequently , this volume expansion results in the distintegration of the white tin metal into a coarse poeder of the gray allotrope. For normal subambient temperature , there is no need to worry about this disintegration process for tin products,due to the very slow rate at which the transformation occurs.
This white-to-gray-tin transition produced some rather dramatic results in 1850 in Russia. The winer that year was particularly cold and record low temperatures persited for extend periods of time. The uniforms of some Russian soldiers had tin buttons, many of which crumbled due to these extreme cold conditions, as did also many of the tin church organ pipes.This problem came to be know as the "tin disease." to gray (or อัลฟ่า) tin,which has a crystal structure similar to diamond (i.e, the diamond cubic crystal structure); this transformation is represented schematically as follows: Specimen of white tin (left). Another specimen disintegrated upon transforming to gray tin (right) after it was cooled to and held at a temprrature below 13.2 องศา for an exteded period of time.