What material is the coffin made of?

There are three kinds of wood for making coffins: The high-grade coffin is “san sandwood”. The second point is "Nanmu." The coffin of ordinary people is "fir". Other woods are generally not used as coffins. Sandalwood is extremely resistant to corrosion. The burial tomb of the Ming Dynasty Wangzhen couple unearthed in Huai'an County, Jiangsu Province in 1987, the same pattern of graves and plaques, only because Wang Zhen used sandalwood to make coffins, the body was still intact when excavated, but his wife was not made of sandalwood. Only the cheekbones are kept.