All throughout the various publications it's stated that it is a 'unique graphite product - highest amongst it's peers (1500ml/g)'. I'm no expert but the fact that they're talking in ml infers to me that that it's volume.
In regards to it being a statistical anomaly, yes it is, and that's why it has so much going for it! Not sure exactly how to copy the thread but there was some interesting points made by Jaffaroo saying it's close to a heat source (volcano), and that makes the graphite more purer and crystallised than it's peers. Anyway hopefully the link below works and can shed some light on your queries.
