This is a bowl showing a core mark from production.

It is from Egypt but the exact location is unknown. Egyptian alabaster workers were skilled at using a variety of tools for manufacture; tube drills, straight saws, circular saws, lathes, and polishers. The marks left in the stone by these tools are the only available reliable source of information about these tools and how they were used. Very few actual tools have been found, and few written or pictorial records describe their use.The maker drilled out the centre of this bowl, as the first stage of shaping the inside, and left the circular mark of the tube drill as as decorative feature. This is a bowl showing a core mark from production. It is made from diorite. It is about 5,000 years old, dating to the 1st Dynasty (3100-2890 BCE) in the Early Dynastic Period.