Japan has just announced another vast discovery of rare earth bearing materials on the ocean floor. This does rather put an end to any possibility of China having a long term lock on the supply of these vital elements.

You might recall a couple of years back there was a similar Japanese claim. There it was that the plumes from underwater volcanoes were rich in rare earths. This makes good sense as rare earths are constituents of pegmatites, pegmatites come from volcanoes. Thus, given that these are underwater volcanoes, instead of the REs becoming part of the rock they’re floating off through the water as dust. Further, the floating through the water part does some of the separation of the REs from the other components (as surface water does some of the sorting of alluvial deposits as they weather out of the same types of rocks) so there were areas of sediment that were RE rich.

This finding is a little different. Almost certainly from the same general source: but now the RE rich material is in nodules just under the silt of the ocean floor. This makes it all rather easier to raise from 5,000 metres down.

There is another issue here. Rare earths are usually divided into two sets the lights and the heavies. The new land based mines (Molycorp, Lynas and so on) don’t have much of the heavies in them. So despite our having more REs to play with, China still pretty much has a lock on the heavy ones, the terbium, dysprosium and europium, that we would really like to have more of. This Japanese find is highly enriched in the heavies. Which rather neatly seems to solve that problem.

This isn’t something that’s going to go into production this year of course. I’d be amazed if it does so this decade in fact. But it does lift the possibility of China retaining a production monopoly.