Another topic that has been recently discussed in the IRC EFnet #tokipona chat room is whether or not we need a word that would mean "rock, stone, metal, mineral".
Until now, I thought of using "wawa ma", meaning "hardness of the earth".
But perhaps the concept is universal and common enough to warrant its own root word.
This tentative word would be "kiwen", from Finnish "kivi" (stone), genitive "kiven".
I will create a poll to see what other Tokiponians think...