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
San Tin the area. The Man clan decided to settle in the area in the 15th century. They dried the marshes and gradually filled them with soil, turning them into 800 hectare of rice paddies. This is reflected by the name San Tin, which means "new field"s. The San Tin areas are divided into nine villages within the area most notable areas are Wing Ping Tsuen (), which is close to the Tai Fu Tai Mansion, and Fan Tin Tsuen (). The areas around San Tin are covered in wetlands hence their main products are cabbages (like Chinese cabbage or kai-lan) and