Hammerscale (archaeology)

Hammerscale is what is left behind after you forge iron like it was done in ancient times. It is the metal version of sawdust. Hammerscale is very useful in archaeology.
Description.
Physical Appearance.
Hammerscale looks like either flakes or spheres. The flakes can be very different in size and shape. The spheres are hollow, and often the same size. Hammerscale is black, light gray, or blue.
Chemical Composition.
Hammerscale was probably made from magnetite. However, later steps in the iron working process have given hammerscale that is more and more pure.
In archaeology.
Hammerscale is used to tell what some iron was used for, how it was used, and who made it.