I think it can be useful to add recipes for redstone, lapis lazuli, and diamond ores, so when player grow his own materials he can expand his farm. I am missing minechem recipe for diamonds and I think it should be there so players can create diamonds artificaly from carbon.
I believe Minechem disables Diamond recipes, to avoid dupe bugs. Since Fortune III can change how much 1 diamond ore is worth. Also i am against adding a recipe to make these ores. I am sure players will be selling ores very soon, since you can just silk touch to get them.
Don't wanna step on any toes, but isn't this a question that comes from laziness? Krhymez did so much to bring mining back to the game by disabling as many ore collectors as possible. ie.: digit miner, quarries and other chunk destroyers. Just get that pick with silky and go mining to find your ores =]