the finish is presently just a coat of natural stain to block moisture absorption
to the right of center is a piece of maple burl and to the left of that is a piece of wormy ... hm ... don't remember what it is but it sure is wormy --- I think it's sassafras but I have to dig out the bowl and check.
NOTE: this bowl has been finished and is now available on my bowl-sale site: www.phinds.com/bowls/
Information on this specific bowl can be seen at: n010