Onyx or Agate is another ornamental and precious Stone that is very small in shape and its color is light. Onyx stone with red, white, and yellow colors is widely used and is one of the most valuable and precious stones. Another name is agate which is polished like Glass and is semi-transparent. The main composition of this type of Rock is silica. 

Sometimes compounds such as aluminum, nickel, carbon, magnesium, and iron can be found in it. Agate can be used to make various Jewelry and ornaments. Jewelry made with this stone is of special importance and popularity among the people. Agate is a small stone with a light color, the red, white and yellow types that are better. 

This stone is semi-transparent and has a glass-like luster. Another name for this stone is agate and its composition is silica, but elements such as aluminum, nickel, carbon, magnesium, and iron are sometimes found in its composition. Agate is one of the most precious Gemstones in the Middle East, which is very popular among people and is widely used in jewelry. 

Agate or Onyx (a type of quartz) is another semi-precious stone; ordinary agate is made of regular chalcedony layers, with most amethyst crystals in the center. The Chemical composition of onyx is silica, but sometimes elements such as Al, Fe, Mg, Ca, Ni, Cr is also placed next to it. Onyx is characterized by its fineness and light color. It is translucent, opaque, and has a glassy luster. 

Agate is white to dark gray and black, yellow to red, light green and blue, and is popular among second-rate gemstones. The best are red, yellow and white. A species that has many mica particles and is shiny is called enchanting. 

After Neishabour Turquoise Mine, the oldest semi-precious stone mine in Iran is Baig Mine. This mine is located in Khorasan Razavi province. Shajr Bamrud agate mine is also in South Khorasan and as the only Shajr agate mine in Iran, supplies most of the raw materials for Opal cutting workshops.

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