Here is a link I found on Ageman vs. Pusaka Tayuhan that states that a Penawang (white iron) made Keris is not a Pusaka. It also refers to each "Kingdom" or Periods as Pusaka.
http://www.nikhef.nl/~tonvr/keris/keris2/keris08.html
My question is, was that true back in the 14-16c, since meteorite was not "available" until 18c (or later)?