Ancient Greeks and Romans
To the Romans, aquamarine stood for friendship, peace and love. An aquamarine carved into the shape of a frog was meant to be a talisman for gaining friends and keeping people from becoming enemies. The Romans also used aquamarine to "capture" the "atmosphere" of young love, and gave the stone as a bridal present because of this.
Also, aquamarine symbolized the sea to Romans. They believed that people wearing aquamarine during a boat trip would be safe from danger, and would have a financially worthwhile journey. This belief was shared by the Greeks.
Ancient Egyptians
To Egyptians in ancient times, aquamarine had a funerary meaning. It was believed to help ensure the safety of the departed as they traveled through the land of the dead.
Folklore of the Middle Ages
In the Middle Ages aquamarine was thought to cure some diseases including sleeplessness, eye problems, the hiccups, and was also used as a poison antidote. Aquamarine was also used as a way of gaining insight/foresight. People in the Middle Ages believed aquamarine to to be the best of stones to use to tell the future. They would form a ball out of aquamarine to use.
During this time, the Romans believed aquamarine was a symbol of love, and as such was used as a symbol of renewal of love in marriages.
New Age
Among other cultural sources, the New Age movement utilizes the Ayurvedic medical system's belief that the body has multiple energy centers, known as chakras. Of the chakras, the New Age movement connects aquamarine with the chakra located at the throat, which is known as the fifth chakra or throat chakra.
Aquamarine is believed to possess the capacity to increase a person's personality and increase a person's' ability to communicate. Aquamarine is also believed to possess the ability to increase psychic abilities, and to heal ailments.
And, like the earlier Romans, the New Age movement connects aquamarine with water.