What wood is a santoor made from?

Sources disagree on the wood of the santoor. A Greater Kashmir column names seasoned mulberry for the traditional Kashmiri box, and a retailer names walnut and mulberry, with sheesham on some modern instruments. Whatever the timber, it must be seasoned for years before carving, or it may crack under the tension of the strings. Ask the maker which wood was used and how long it was seasoned.