Most materials I find or make myself. I sell a variety of materials for making knife handles. I make knives myself and am always seeking interesting handle material. You might look all around the web site at various raw materials. But some material I cut with the knife maker in mind, that I know will work and has been cut specifically for knife makers. Most of the wood under 'raw wood' is good for knives as well, but here are some materials to glance through all in one place. Most of these materials I find or create myself so can answer questions on suitability use care etc..
Mammoth ivory chunk 2 pounds
Mammoth ivory chink 1 pound
Mammoth ivory chunk 1 pound 12.9 ounces.
Mammoth ivory chunk 1 pound 2 ounces
Mammoth ivory chunk 6.8 ounces
4 x a tapered 3 to 3.5 x ½ tapers to ¼ inches. Fairly solid but one layer looks like it wants to delaminate (see end picture). I have done nothing so you stabilize if you wish or pop that layer and get two pieces. This is one piece all natural, no dyes or work done. Partly because I see some color waves of blue and gray that could be awesome if handled right. No enhancement needed. Great for knife scales but would scrimshaw well or work as a carving.