Water? In MY upper mantle?

[Dalex]

http://en.wikipedia.org/wiki/Ringwoodite

Ringwoodite is notable for being able to contain hydroxide ions (oxygen and hydrogen atoms bound together) within its structure.[4] Combined with evidence of its occurrence deep in the Earth's mantle, this suggests that there is from one to three world ocean's equivalent of water in the mantle transition zone from 410 to 660 km deep.[5][6]

Even with microvoids, you would have process the rocks to get it.