milkstone

From milk +‎ stone.

milkstone (uncountable)

1. Any stone, such as galactite, thought to increase milk production in mammals.
2. Certain white stones.
3. A hard body that forms in a mammalian udder.
4. A layer of scale that forms on milk-processing equipment, mainly formed of cations of calcium and magnesium.

• “milkstone”, in OneLook Dictionary Search.

• skimelton