Last month after purchasing a woodturner's substantial collection of aged burls and other assorted turning chunks, I had to identify them. Most of the species I had never seen before plus many were hacked up with a chainsaw, aged, dirty, with or without bark.
One in particular I found interesting. Clueless, I took a hand power planer and shaved off its rough chainsawed end. As I smoothed it up I could see very distinct ring porous annual rings and the wood was heavy which made me think it was some kind of oak. However, the color was a very deep brown, too dark for our local oaks. I took a couple more swipes with the planer and a yellow streak appeared. As I went deeper into the fresh wood it turned bright yellow.
Now I went to my textbooks. Red Mulberry has a narrow yellowish sapwood and its heartwood is "orange-yellow to golden brown, turning russet-brown on exposure." Its specific gravity is .61 (comparable to .62 of Yellow Birch) and is very similar to Osage Orange. However, if you take a damp cloth and rub the yellow wood it does not impart any of the color to the rag.
Red Mulberry can be used for furniture, interior finish, caskets, fence posts, wagon stock and cooperage. The heartwood is extremely rot resistant. It grows throughout the East, Southeast, and Midwest and can be 2' - 3' in diameter, 50' - 70' tall. It has an ovate leaf 3" - 5" long by 2" - 3" wide but can also have 2 or sometimes 3 lobes. It is easy to identify with its juicy and edible fruit about an inch long which looks like an elongated blackberry, red at first then purple when ripe. It grows in fertile, moist soils and the bark on mature trees has dark, reddish brown scaly plates.