Hi ER, Buffett has invested $80 million in a tungsten mining project in South Korea........So just maybe he is looking for the next big thing (Graphite) .......As you say,
Buffett loading up on Graphite, has a very nice ring to it 
As he has invested $80 million in a tungsten project back in 2012, I'm sure he could find some pocket change for TON.....
Also from what I remember, the tungsten company he invested in, is having a bit of problems in South Korea, they seem to be having a lot of movement from within the board over the last 12-18 months, directors coming and going, which isn't a good thing for a compny.
I have also shares in an Australia tungsten company, which has a tungsten mine in the UK!
http://moneymorning.com/2012/06/11/why-warren-buffett-is-loading-up-on-tungsten/
It's all about the end game
