Hello everyone!

I purchased this at an estate sale because I simply thought it was neat. Yet I thirst for more information. Could anyone please tell me what it is?

Item info:

It is made of metal.
It is magnetic.
On each side of the cube there are different size holes. (none the same size)
It measures 2 1/2" x 2 1/2"
It weighs 2 lbs 6 oz
On one side it is marked 65 France

My theory:

It is a mold for precious metals (Casting I think its called)