What does 'spalted' mean?
Spalting is caused by certain white-rot decay fungi growing in wood - primarily hardwoods such as maple, birch, beech, and dogwood. The fungi create colorful, sometimes fascinating patterns in the wood usually evidenced by contrasting dark lines. The unusual color lines can range from black to pink to gray and even a variety of colors in the same piece of wood.
If the decay progresses too far the wood gets very weak and spongy and generally useless. However, woodworks crafted from spalted wood generally take on a distinctive flair of their own. This is why spalted wood pieces can be highly prized, higher priced and often sought-after by woodworks collectors.
As the wood dries the fungi go dormant and are considered to be encapsulated by many modern finishes. This makes them safe to handle, but such pieces are not recommended for contact with food as a general rule. This is why you shouldn't see spalted salad bowls.