Jasper is an opaque and finely crystalline variety of quartz. The chemical composition is identical to that of agate, flint and chert. The colors are variable, from yellow through red and reddish brown to green. Jasper stones are cut and polished to be set in jewelry. The name jasper is taken from Latin and Greek from a Semitic language and means "spotted or speckled stone". The main sites of jasper are India (Dekkan plateau) and Mexico (yellow), Germany (red) and Africa, Australia, Brazil, Egypt, France and the US (other colours). Jasper has been worked as a gemstone since ancient times. For example, they were used to make seal stones, small cut stones and gallantry. Jasper was credited with magical powers. In ancient times it was called the mother of all stones. It is used today in cabochons, table cuts and crafts. Imitations are made of glass. The Egyptians and Greeks already used jasper to enhance sexuality and to achieve early pregnancy. Yellow jasper worked as a rainstone for the Indians. A number of medicinal properties are attributed to jasper, such as stress reduction, weight loss, stomach complaints and liver problems. Jasper belongs to the zodiac signs Aries, Virgo, Cancer and Scorpio, according to various literary sources. In the Christian scripture Revelation 4:2-3 it is written: At the same time I was entranced. There was a throne in heaven and someone sat on it. The one sitting there had the appearance of jasper and sardar, and around the throne was a rainbow that looked like emerald.