This rustic knife is one of my favourite pieces to date. Made in 26C3 high carbon steel I have managed to achive a gorgeous 'hamon' by differentially heat treating the blade.
 
This is done by applying clay to the spine of the knife so that during the oil quench, this portion of the blade cools less rapidly, producing the ghostly line which now separates the hard edge from the softer spine, giving more flex and just generally looking pretty awesome.
This is the same technique used to give the blades of Japanese Samurai swords their characteristic wave.
I have then used various acid etchants and techniques to increase the contrast and bring this hamon out further.

The handle is made of locally collected and then stabilised apple wood. This beautiful wood has so much going on in it, chock full of different colours, textures and grains, the latter of which I have taken great effort to match the flow of the 'hamon' so that the dark line runs seamlessly through both the blade and the handle.