Agate is one of the first stones used for decoration and jewellery. Its name is associated with Achates River (now called Dirillo River) in Sicily, where it was quarried in the distant historical times. Agate stones are distinguished by their extremely high diversity in form and colour. They are composed mainly of chalcedony with alternating dark and light stripes, which can be concentric, parallel or a combination of both. Each stone has a unique pattern; sometimes they form different texture and pictures that resemble landscapes (landscape agate), moss (moss agate) and others. The shape is often spherical and thus called agate geodes ("geo" - a sphere, a ball). They are often hollow or filled with crystals of quartz, amethyst and morion.
The best known deposits of agates are located in Brazil, Uruguay, India, Russia and others. In Bulgaria, agate deposits are found mainly in the regions of Kardzhali and Shumen.
Agate is mainly used in jewellery and for the make of decorative objects (boxes, ashtrays, vases, etc.), but because of its high hardness (6.5–7) it is also preferred material for laboratory containers for the grinding of samples of solid substances. Agate talismans and amulets are believed to protect of various natural phenomena, magic, accidents, etc.
According to some traditions Agate is the stone of fidelity. When a person donates an agate, it is said to create a feeling of goodwill towards donor.
The agate relieves stress, develops eloquence, improve eyesight and helps children to fight off fear.
In one health station manuscript from the sixteenth century, agates are described with the following lines: "Agate helps with seizures and exorcises evil spirits, helps with stomach aches and brings sweetness. The same stone if placed in water for three days and then given as a drink to a woman, who is about to give birth, she will deliver easily. The same water, if you give it to a girl, it can tell whether this girl is immaculate, if she is unclean – the water won’t stay retained and it will flow out of her if the girl is unblemished, the water will stay in her and won’t come out..."