Greenstone (jade) was highly valued in New Zealand because it was durable, beautiful, and precious. Greenstone is found only on the west coast of the South Island and was used as a means of exchange. In times of trouble, peace could be secured by ending warfare through a political marriage. Peace, thus established, was often likened figuratively to a greenstone door as both the woman and the peace ceremony were seen to be durable, strong, and valuable.