Yes cornel is a very hard wood. A friend before trying to make knife handles of dogwood but said that 95 percent of them burst or izmetnali. And I have not seen dogwood with some good patterns. As hardness boxwood is stronger, more rare because it grows very slowly, and too many of treason handle fultang must be with beaded handle. I would recommend you acacia. very strong wood and buds are very good pattern. There are many interesting materials for the handle of a knife with a decent price, it all depends on what you're looking for. These are three trees: alder Rotten, rotten wood and acacia. As I write this rotten wood does not have to worry, it's very well stabilized with resin under vacuum, and so it is harder thing as Micarta.