Agate is a banded form of chalcedony, a kind of quartz built from crystals far too small to see. Its layers of color can be as fine as pencil lines or as broad as stripes. In China it is called manao, and Buddhist sutras count it among the seven treasures.
How the bands form
Most agate grows inside gas bubbles left in cooling lava. Long after the rock hardens, water carrying silica seeps into the hollows and leaves layer after layer of chalcedony. Iron compounds tint the bands. Geologists still do not fully understand how the even banding forms. At 6.5 to 7 on the Mohs scale, it is hard enough for everyday beads.
The ancient Greek writer Theophrastus said the stone was named for the river Achates in Sicily. Some scholars think the river took its name from the stone instead.
Why so many agates are dyed
Agate is slightly porous, so it takes up dye well. Agates of intense pink, blue or green are often dyed. Stone workers in Idar-Oberstein, Germany, refined the methods in the early 1800s, and much of the agate sold today has been stained in some way. Some dyes can fade with heat or long hours of sun.
Moss agate is pale chalcedony with dark, branching inclusions of iron and manganese oxides. It has no bands, so some references say it is not a true agate at all.
Red agate and carnelian
Red to orange chalcedony colored by iron oxide is called carnelian, a name usually traced to the Latin for the cornel cherry. Chinese often calls the same stone hong manao, red agate, so the two names overlap. Heating has been used for centuries to deepen the red, and much carnelian on the market today is heated or stained agate.
Agate in Chinese and Buddhist tradition
Manao means "horse brain." In the 3rd century the poet Cao Pi wrote that the stone came from the Western Regions and that its interlaced lines looked like a horse's brain. Another theory holds that the name began as a translation of a Sanskrit word in Buddhist texts. Chinese translations of the Lotus Sutra and the Amitabha Sutra name agate among the seven treasures that adorn the Buddha lands. The lists vary from sutra to sutra, and scholars still debate which stones some of the old names meant.
Red is the color of luck in China. In their own zodiac year, many people wear something red, such as a red string bracelet, to ward off bad luck. A red agate bead on a red cord joins the two customs.
Caring for agate
Wash agate with warm water, mild soap and a soft brush, then dry it well. Keep dyed stones away from acetone, alcohol and strong sun. Take bracelets off before you swim or clean, and store them in a soft pouch. Find more styles among our bracelets.
Agate at Buddha.store
- Red Agate Chinese Zodiac Red String Bracelet
- Red Agate Bead Bracelet with Heart Knot
- Coffee Striped Agate Bracelet
- 108 Bead White Agate Mala Bracelet
- Tibetan Nine-Eye Dzi Bead Agate Bracelet
- Moss Agate Balance Ring
See every piece in our Agate collection.
