Each species of hardwood has its own set of properties, however they have some properties in common. Hardwoods normally have broad leaves and come from deciduous or broad-leafed evergreen trees. Hardwoods grow slower than softwoods. Evergreen softwoods grow faster than deciduous hardwoods, and can grow to a larger size. Some hardwoods are excellent for carving. One of the hardest hardwoods is black ironwood which is recognized by the Guinness Book of World Records as the heaviest wood. Ironwoods are so dense that they sink in water rather than float as other woods do.