I'm not a dev, but from a player point of view and judging by how the Planeshift project is going, I would wager that ruby crystals will probably be useful in the future with things like weaponsmithing, and jewelry. However, being that some of those things are a bit of a ways away, and it is possible to acquire more of them at any time if you are willing to spend the effort, I wouldn't keep it around for that eventuality.
Hope this helps