Angelite 4mm Round 15-16 Inch Peach Viking explorers used thin pieces

Viking explorers used thin pieces of Iolite as the world’s first polarizing lens to help them determine the exact location of the sun for navigation

Australian Butter Jasper is a relatively new variation of Jasper that definitely meets that criteria

It is made up of Calcite or Calcium Carbonate

Green Lodolite is Quartz with inclusions of sand

gray and peach

Angelite 4mm Round 15-16 Inch Peach Viking explorers used thin piecesA natural blue form of calcium sulfate, it raises the state of conscious awareness and facilitates contact with your angels. It is mined in Peru. It's also known as Angelita and Angelite Quartz. Mohs hardness 7.