Hand crafted from sterling silver. This gorgeous ring is designed by Alan Myerson in Australia and ethically made by skilled artisans in Mexico. This ring works well for both men and women and is available in sizes 6 through to 15. Approximate diameter of Mayan Calendar: 19mm Approximate weight: 17g Time was extremely important to the Maya, they made elaborate and accurate calendars and used them in charting the movements of the sun, moon, stars and even planets. These calendars served a variety of purposes both practical and sacred. They were used in astronomical calculations, recording important events, the reigns of rulers and their conquests and also in divination.