lignum vitae is an extremely dense, heavy, hard wood. I can't imagine that any cricket ball headed mallet would be harder. Lignum used to be used to make bowling woods due to its durability and weight, also for ship's bearings. I used to use small pieces to make certain types of fishing floats . Its main attribute for that job is that it sank, thereby making a faster cocking float that cast well and required minimal additional weighting down the line. It is an absolute pain to work with though, being so hard that it quickly takes the edge off any tools used.