Belt Buckles approximately 3 in X 2 in. The Stone is Rainbow Obsidian. 
 
Rainbow Obsidian is one of many varieties of obsidian. The rainbow obsidian will have a rainbow of colors. The colors in the rainbow obsidian caused by reflections off the microscopic bubbles and nanoparticle inclusions of minerals. Can be found in US and Mexico with a hardness of 5-6.