(IDEX Online) - Scientists now believe there is water far deeper below the earth's surface than originally thought - thanks to rare inclusions in diamond sent for routine grading by GIA.The 1.5-ct D-color gem recovered at the Karowe mine, in Botswana, contained minerals which turned out to be hydrous (water-bearing).Examination of the diamond using advanced, non-destructive methods concluded that water can be found at a depth of at least 660km - far deeper in the earth than previously believed.The research was led by Dr. Tingting Gu, who was at the time a GIA post-doctoral research fellow.His team used FTIR, Raman spectroscopy and X-ray diffraction to assess the exceptionally rare type IaB diamond, and identified the water-bearing inclusions as ringwoodite, enstatite and ferropericlase.Pic shows the 1.5-ct diamond with (inset) the highly-magnified mineral inclusion (image show field view under 1mm).