Ljósbjörg Petra María was born on Christmas Eve in 1922 in a small traditional farmhouse on the northern shore of Stöðvarfjörður, called Bæjarstaðir.
Petra began to build her mineral collection when she and Nenni bought their house in 1946. The reason was that for the first time she could keep all the stones she found in one place. Before that time she had found a lot of minerals that she left behind because she couldn't store them. In a way her collecting work had taken place in her mind until she could keep her stones in one place. "I knew where to go when I started my true collecting work", she explains.
Petra's interest in the wonders of the world is rooted in her respect in everything that belongs to it. In her one words: "I remember thinking that it was horrible to be unable to write a song or a poet about all the beautiful things that I have witnessed, to be able to give something back. I have seen such beautiful things, incredible beauty that I can't put in to words. Many times I sat down and admired God's creation. It's all so variable." These words prove that, in her heart, Petra is an artist and she uses the stones as her material for artistic expression. Her guestbooks show that many of her guests experience her museum as a work of art. So in her own way she has fulfilled her dream of being able to "give something back", even though she doesn't realize it.