Data from: Ice-VII inclusions in diamonds: evidence for aqueous fluid in Earth’s deep mantle

Water-rich regions in Earth’s deeper mantle are suspected to play a key
role in the global water budget and the mobility of heat-generating
elements. We show that ice-VII occurs as inclusions in natural diamond and
serves as an indicator for such water-rich regions. Ice-VII, the residue
of aqueous fluid present during growth of diamond, crystallizes upon
ascent of the host diamonds but remains at pressures as high as 24
gigapascals; it is now recognized as a mineral by the International
Mineralogical Association. In particular, ice-VII in diamonds points
toward fluid-rich locations in the upper transition zone and around the
660-kilometer boundary.