In 640 BCE Necheps wore a jasper around his neck to cure his queasy stomach. In 1969 Barbara Anton (a graduate Gemologist from the Gemo-logical Institute of New York) advised a friend, who had suffered from irregular menstrual periods for years, to wear a yellow jasper pendant. So long as she wore it,her periods came regularly on a twenty-eight day cycle.
Any good book on gems and minerals will give you full descriptions of the many varieties of stones available in the full spectrum of color. Rubies, emeralds, sapphires are obvious examples of red, green and blue, but there are many other equally effective yet far less expensive stones available. Here are a few stones, together with the colors in which they can be obtained plus some of the ancient beliefs regarding their properties.