A collector and a naturalist are two terms that have been used to describe Petra since she was a little girl. From the day she opened her eyes for the first time she perceived her surroundings differently from most of us and it is almost as her parents knew that when they named her. The word "Petra" simply means "stone" in Greek.
Petra began building 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 and stones but she them left in their place 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 explained.
For the first two decades of her collecting work, Petra almost solely looked for stones in the north slopes of the mountains in Stöðvarfjörður. She simply walked out of her front door and up to the mountains above her home. The reason was that it was extremely hard to travel around this part of East Iceland before 1962. The roads were primitive and no bridge over the river Stöðvará. Stöðvarfjörður was in that sense very remote and that limited Petra's possibilities to collect stones in neighbouring areas; therefore her minerals are mostly found in Stöðvarfjörður. Later she limited her collecting work to East Iceland and her collection is therefore first and foremost an example of the types of minerals that is to be found in that part of the country.
Many people think that a mineral collector must be a little bit weird and through the years Petra heard this from many different directions. Some people told her that she should be doing more "productive" things, like baking bread or doing something around the house that was more becoming a housewife like herself. Petra said she could understand that it appeared a little bit strange to spend so much time looking for stones, but on the other hand she did not care what others thought about her.
It is obvious that Petra had a special talent when it came to locating a beautiful stone. A number of people can tell stories of when Petra picked up a magnificent mineral from where they had been walking minutes before. Petra compared mineral collecting to hunting or fishing. She found something new in every stone and the thrill of finding or "hunting" a new one was one of the reasons she returned to the mountains for all these years, even though that feeling was mixed with a little bit of remorse. Petra always believed that the stones belonged to those who live in the wild nature, whoever they might be.