This rock is formed on the planet dranitous, it's a mix of reshiram and bulbasaur and the liquid of the planets core witch is called trimanous that turns into a rock when cooled but remains a liquid inside the bulbasaur and in a coating of red Dimond. Due to the planets extreme gravity and heat underground. Theses two minerals and liquid combine together over thousands of years forming Zekrom.
What is a mineral:a solid, naturally occurring inorganic substance. And what is the difference between a mineral and a rock: A rock is an aggregate of one or more minerals whereas a rock may also include organic remains and mineraloids.