Named after the Kona Hills south of Marquette County, Michigan where it is found. Kona Dolomite is an ancient rock in which formations of fossil stromatolite (blue-green algae) occur. The stone is between 2.1 to 2.2 billion years old. These stromatolite formations are from some of the first life on earth. These fossil formations are found in the lower eras of the Middle Precambrian Period.