“Agate is a gemstone with countless hues and designs that belongs to the Chalcedony family. Its colored striations mean each stone is unique.”
The name Agate derives from the river Achates in Sicily, now called the Dirillo.
Chemical composition of Agate
Agate is a striated Chalcedony with concentric bands which may be of different or a single color. Agate belongs to the group of microcrystalline Quartz.
Extraction of Agate
Agate is formed in the cavities of volcanic rock in the round or almond-shaped nodules. The typical striations of Agate are caused by the oxidation of manganese, iron and other minerals.
The history of Agate
Agate was a highly valued gemstone in ancient times, for both its beauty and its hardness. It was already being used in Asia for decorative and practical purposes (such as the production of vases) in 3000 B.C. In the gemstone world, it has been used as a precious stone, for cameos and for seals. In ancient Rome, engraved Agate was particularly popular. People used a particular carving technique that allowed a figure or design to be carved into the stone.
Agate is mentioned in the Bible in Exodus as one of the gemstones of Aaron’s breastplate. Sardonyx, a variety of Agate, is one of the twelve stones that form the foundations of the Wall of Jerusalem.
Agate was also a popular gemstone in medieval times. For instance, tying an Agate to a bull’s horns was said to bring good fortune for the future harvest.
Properties of Agate
Agates display colorful surface striations; the individual layers of these marvelous colored bands may be transparent or opaque, with strong fluorescent hues of yellow, white or brown.
The different colors are caused by the presence of iron and manganese. The strata in Agate may present a variety of different color intensities, but the interior of the geodes are virtually identical.
Varieties of Agate
There are a number of different varieties of Agate with different colorations.
Botswana Agate displays striations with particularly beautiful colors, ranging from warm earth tones to intense oranges.
Blue Lace Agate
Blue Lace Agate displays a variety of blue toned striations on the outside of the geode.
Dendritic Agate is a translucent or transparent white Chalcedony with dendrites.