Voxel Types List of all player-accessible voxels
These voxels have special properties, mostly for artsy editing
These voxels have no game properties. They're just pretty to look at. The game sets them with default colors, but you can edit them for each model.
These voxels have game properties for mining, blasting, shooting, physics, etc. You'll have to wait for those features to be implemented.
Look forward to dirt, water, and other exciting cubes.