African blackwood: Dalbergia melanoxylon: Technically a rosewood, African blackwood is a great choice. Its more stable than ebony, harder, just as heavy and far more stable and crack resistant. The wood tends to be black with subtle greyish grain running through it that personally, I find much more interesting the solid, featureless black of ebony.
All the blocks photographed are MUCH darker and blacker than they appear in the photos. Capturing the accurate black color, and revealing any of the subtle silver grain at the same time is very difficult. I try my best, but i always trend towards overexposing the photo and showing the grain. But these blocks are BLACK. Think midnight block with a faintest hint of purple through them.