Our saw mill manager had two hard maple burls that grew on adjacent trees on the same stump. They were just fat spots that I wouldn't have considered burl. the bark was tight and in decent shape. The burls were solid. The following are finished bowls from the burls. I only got three bowls, should have had four but one half wasn't too oval shaped to make a bowl. All are finished with danish oil, buffed and waxed. Cracks were filled with epoxy glue and wood from the burls - turning shavings ground up.
I am a amazed how dark the wood is for hard maple.
The first is natural edge - 8" diameter and 2" high (First three pictures). The second bowl is 8" diameter x 1-1/2" high (4th thru 6th picture). The third bowl is 10" diameter x 2-1/2" high.(7th and 8th picture)