I should have elaborated more, it is all in my head but I tend to forget that it was not typed.  The stone can only show its power through a weapon, meaning that it is just a plain stone until it is forged into the hilt of a specific type of weapon.  The crafting of that weapon has to be done exactly right, meaning the exact compound make up of different metals at the right temperatures at the right times throughout the smithing process, for it to "unlock" its potential power.  You can not wield it as just the stone by itself.  it is purely an augmentation. I shall edit this into that.  The reason the power of that stone is not stated as to what it is is because the character does not know, as the "Guardian"s were never told.  AKA Vivex is never going to use it herself as her species inherently does not care for such type things nor the gain they could obtain from it.