A theory goes that the term agate was derived from the river Achates located now in Sicily. This was the name given to the stones found on the banks of this river. Another theory states that this term refers not to a single stone but to an aggregation of different variants of the mineral silica, namely chalcedony.
Agates come in many types with different names:
- Mexican agate, with a single eye also known as "cyclops agate."
- Dendritic agates with beautiful patterns.
- Turritella agate refers to the fossilized Turritella shells on the chalcedony base.
- Agatized coral is known as Petoskey agate.
- Greek Agate is the name for a pale white agate found in Sicily in 400 B.C.
- Other forms comprise of the Carnelian agate, Botswana agate, Plume agate, Tube agate, Fortification agate, Fire agate and Mexican crazy-lace agate
Possessing an agate is said to bring tranquility, soothe one mentally, prevent contagious diseases, promote articulation, bring good fortune, and bring victory over enemies. It is sometimes said to give the bearer the power of invisibility.
In Africa it is believed that agate can cure scorpion stings and snake bites.
Persians believed that magic possessed agate rings which played a crucial role in their work.
Today, agates are used mainly in chemical and jewellery industries to create ornaments such as pins, brooches, clips, paper knives, inkstands and seals. Since it is hardy enough to resist acids, it is used to make mortars and pestles to crush chemicals.