Agate is a translucent, sometimes opaque variety of quartz and a sub-variety of chalcedony. The chemical structure of agate is identical to jaspis, flint, hear dial and is often found together with opal. The colorful, striped specimens are used as gemstone. The name agate comes from the Greek Ἀχάτης, Achates, the name of the current river Dirillo in the south of Sicily, where agates and other chalcedonies found. Traditionally agate was worn as a lucky stone, or to cure. There were also consumer items like buttons made of agate. Some medicinal effects is attributed to agate, such as protection during pregnancy, for headaches, skin disorders, and balance disorders. Agate belongs according to various literature on the zodiac Aquarius, Taurus, Scorpio and Gemini. Agate Connections form as a solution of silica in cavities in older rocks. The stones can be artificially stained in order to obtain color combinations that are more vivid than those found in nature. The major sources of agate are Brazil, Uruguay and the United States (Oregon, Washington and around Lake Superior). Closer Netherlands and Belgium are also agate found in the Hunsrück in Germany. Chemical composition: SiO 2 + Al, Ca, Fe, Mn Crystal System: belongs to chalcedoonachtige quartz crystal, trigonal. Fission: None. Color: light blue or gray but can also be green stripe color: none. Shine: glass gloss, matt, satin finish. Hardness (Mohs): 6.5 to 7. Average density: 2.65 kg / dm3. Transparency: transparent to translucent.