Walnut from various parts of the tree give it the variety of color. Pieces were glued to 3/4 MDF with Tightbond 2 wood glue. It was a gift for a Grandson's new apartment.
Thanks everyone, the finish is a homemade wax/mineral oil rub that I use for cutting boards. Probably unusual for a countertop but we'll see how it works out. The unit goes in a laundry area anyhow so it won't get a lot of heavy use.