Diamond cutting tool and method for manufacturing the same

A diamond cutting tool comprising a cutting edge portion containing single crystal diamond or binderless polycrystalline diamond and graphite, wherein

• a surface of the cutting edge portion exhibits Raman spectroscopy peak intensities wherein a ratio R1 of Ig1 to a sum of Id1 and the Ig1 is equal to or more than 0.5 and equal to or less than 1, where the Id1 represents a peak intensity of first carbon in the surface, the Ig1 represents a peak intensity of second carbon in the surface, the first carbon represents carbon that forms the single crystal diamond or the binderless polycrystalline diamond, and the second carbon represents carbon that forms the graphite, and
• a plane located at a depth of 1 μm from the surface exhibits Raman spectroscopy peak intensities wherein a ratio R2 of Ig2 to a sum of Id2 and the Ig2 is equal to or more than 0.01 and equal to or less than 0.3, where the Id2 represents a peak intensity of the first carbon in the plane located at the depth of 1 μm from the surface, and the Ig2 represents a peak intensity of the second carbon in the plane located at the depth of 1 μm from the surface, and
• wherein content of the graphite decreases substantially continuously from the surface to the plane located at a depth of 1 μm from the surface.