Comment by BruceM

The Nito Project on Youtube has 3 nice videos about this:

* https://www.youtube.com/watch?v=BDSee1-4bUI (How to make...)

* https://www.youtube.com/watch?v=pfBGGuezus8 (Shiny Graphite Ball made from Clay and Graphite)

* https://www.youtube.com/watch?v=jG7wHTmKtjQ (Textures in Dorodango)