I think for now a simple smooth mirror type material (with a not quite perfect shine), as well as the lighter area along the blade.
The material you have now looks reasonable but I would take off the noise/speckle effect, it makes it look like low quality casted metal, which these swords are of-course generally not.
If you wish to have some impurities on the metal I would suggest perfecting the model first, then you can detail those impurities with regard to the shape of the contours etc. Checking many references as to what/where these impurities may be, looking at any dints/scratches/oil from humans/structure of the metal/etc and how they effect the look.
About the light material along the blade, this is the hamon (or tempering pattern). This occurs because of a special clay that is painted along the blade but either lightly or not at all on the cutting edge. This causes the area covered in clay to cool slower thus the metal being softer and more flexible once cool. On the edge of the blade which is uncovered, it will cool quicker, causing it to be harder but more brittle.
So this pattern loosely follows the shape in which the clay was applied and does not have a perfect transition.
Here's a link to some patterns and nice pictures of the metal. http://budostuff.com/swords/hamon.htm
If you open the images in a new tab some have larger available.
Mostly now I think it's about the model of the blade. It appears to have no weight, this because of the lack of detail on it and (what appears to be) 100% sharp transitions - it needs some micro bevelling type thing going on, even the blade edge will not be perfectly sharp. Certainly it needs something where it joins to the handle.