Ringwoodite

Ringwoodite is a mineral. It is a type of olivine which is formed at high temperatures and pressures in the Earth's mantle between 525 and 660 km deep. Olivine is a magnesium iron silicate. This mineral was first identified in a meteorite in 1969.Binns R.A. et al 1969. Ringwoodite, natural (Mg,Fe)2SiO4 Spinel group in the Tenham meteorite. Nature 221, 943-944. It may be present in large quantity in the Earth’s mantle.

Ringwoodite is notable because to contains hydroxide ions (oxygen and hydrogen atoms bound together) in its structure.Ye Y. et al 2012. "Compressibility and thermal expansion study of hydrous Fo100 ringwoodite with 2.5(3) wt% H2O" . American Mineralogist 97, 573-582. This suggests that there is from one to three times the world ocean's equivalent of water in the mantle's transition zone from 410 to 660 km deep.Oskin, Betty 2014. Rare diamond confirms that Earth's mantle holds an ocean's worth of water. Scientific American. March 12, 2014. 

 References 

Category:Nesosilicates