This rock was formed nearly eleventy million years ago, when dinosaur toenail clippings were put under great heat and pressure. This would have occured in volcanoes, which then launched the rocks into the stratosphere during eruptions. The heat from the descent would purify the rocks, and when they landed cavemen and molepeople would compete furiously for them due to their religious significance.

After the extinction of the molepeople in the seventh century B.C.E., all rocks like this would have fallen into human possesion. From the unique patterns on this rock I can tell it spent at least several hundred years in Egypt. It is a little known fact that the ancient Egyptians used dinosaur tonail clipping based rocks to help in the construction of the pyramids by summoning aliens. The Pharaohs also used them to call up the waters of Nile, but they sadly never realised that the rocks were useless and the power was inside them all along.

After the Roman conquest of Egypt (largely caused by the Pharaohs never realising their true potential), this stone was presumably captured and brought back to Rome in chains. Some of the wealthiest Romans would eat stones of this type, usually served with dodo meat.
Eventually, some Roman general might have brought this stone to Britain during the conquest of the island. After consumption, the stone would have been thrown into the sea, along with some soldier the general didn't like, as an offering to Poseidon. Now, the stone was it a posion to wash up on the shores of Ireland, which was then known as Leprechaun Island.

At the time, Ireland was completely under fairy dominion. The most famous kind of fairy were the leprechauns, though there were many others. Although the people of Ireland had slaved away for many centuries, these rocks ushered in a new age when it was discovered that the fairies had one weakness - dinosaurs.

When the dust of the revolution had settled, the people of Ireland had to decide what to do with the rocks of their salvation. Eventually, it was decided to spread them across the island, so the dinosaur gumption contained within them would make Ireland inhospitable for all fairies. This plan worked, and Ireland has been free of the fae since 362 C.E. In all this time, the rocks have stayed on the island, keeping us safe from the fairy menace until the end of time.