Made from silicon dioxide, it has a glassy (vitreous) lustre, and is often used to make brooches and pins. It can also resist acids and has been used to make mortars and pestles to press and combine chemicals.
Many Agates originate in cavities of molten rock, where gas bubbles trapped in solidifying lava are replaced with alkali and silica bearing solutions. Formed as a banded round nodule (like the rings of a tree trunk) and has bands of colours of bands – Riband Agate.
In Wales, agate is linked to who was the goddess of death and fertility. She is the queen of the west, of water and of the autumn season. Ceridwen is the creator of magic and the queen of witches.
Agate is associated with Archangel Michael.