Master Crystal?

Hi there folks

This is a question directed at the reiki and crystal workers here. Having done my celtic reiki 2 attunement my RM has suggested I find my master crystal. So this past week I've been playing with my (relatively small, going from the pics around here!) stone collection and its really inspiring to start to truly appreciate the worth of my stones. I've also picked up some quartz points today to play with some grids

But Ive googled and cant seem to find much on master crystals. Which crystal is yours? How did you find it? I'd love to hear some stories!

My Black Tibetian Quartz is the center of my grid and I keep it surrounded by my clear quartz pieces. It really is impressive how powerful it can be because it is smaller than all of my other quartz stones but it simply has a unification quality to it, and a vibrational frequency like no other.