What is the beard on the bull on the famous sumerian harp made of?

The beard on the bull depicted on the famous Sumerian harp, known as the "Lyre of Ur," is made from a material called lapis lazuli. This semi-precious stone, prized for its deep blue color, was often used in ancient Mesopotamian art and jewelry. The harp, which dates back to around 2500 BCE, showcases the intricate craftsmanship and artistic skill of the Sumerians.