I'm not sure if everyone knows this trick or not but obtaining diamonds in tekkit is fairly easy, this also works with any other EMC compatible item. For this you will need; two redstone engines, two energy condensers, one chest of any kind, (I used an alchemical chest) wooden transport pipes, stone transport pipes, blaze rods, a macerator, two generators, and a couple redstone torches. To start, fill a chest with blaze rods, next using a redstone engine and wooden pipes, feed them into a macerator. The macerator will macerate them into five blaze powder. (I advise overclockers to speed up the process.) Next feed the blaze powder into an energy condenser, and set the item you want to make to a blaze rod. How this works is blaze powder has an EMC value of 768 and blaze rods have an EMC of 1,536. So for every blaze rod macerated you get about 2.5 blazerods back. Now the last step is to feed the blaze rods in the condenser into a condenser with diamonds. This also works with bones and bonemeal although the blaze rods will be quicker. Hope this helps, if this wasn't clear enough or if you want more Tekkit tutorials feel free to PM me!