Sounds wicked.
First, take a look at CoreWorldResources. Start making your own. That's going to be the unbuilt shard. Pay special attention to the tag <Type>, you have to make that something unique (that is the tag the game uses to identify which building goes on top).Also make sure to set rarity to 0, this should prevent it from random spawning.
Secondly, take a look at EmpireUnlimitedImprovements.xml or KingdomUnlimitedImprovements. Look up one of the resource buildings. Notice that the <Type> from above has now become <SupportedResourceType> to decide which kind of resource it can build on.
I posted an example of an elementium mine in another thread, and this was the result:
http://thedyinggrounds.com/Elemental/testmod_worldresource_elementiumnode.xml
http://thedyinggrounds.com/Elemental/testmod_allfactionimprovementelementiummine.xml
Once you've made the worldresource correctly, it will show up in the map editor, under resources, at the very bottom.
Edit: As for what you can and can't do with the shard. You can't make it increase all spelldamage by 50%. What you can do is make it "act" like one of every other type of shard (I don't know the result if you add "half" a resource of that). If you do that, all the damage spells will get +100% damage (well, they would if the game worked! or you can use the bugfix mod). The global buff to research is no problem.
