What slaves were especially valuable?

The slave trade flourished in ancient times, and due to the abundance of slaves captured in the conquered states, they were divided into the categories of the least valuable and most valuable. The most valuable slaves were those who possessed some significant skills and abilities: for example, they knew how to make jewelry, forge weapons. to weave, etc. No less, and sometimes more than them, were appreciated those who were captured and became, accordingly, slaves. beautiful women who were expected to be sold into harems.