It was formed during the Miocene Period.
Priday Plume Agate is found at the eastern edge of the Deschutes Basin, northeast of the town of Madras, Oregon.
Priday Agate was first discovered in the 1920's by Leslie Priday on his ranch Priday Ranch, which was purchased in 1976 by Richardson’s Rock Ranch. Richardson’s Ranch is a large area that host pay for dig rock hounding. It is said that most of the high grade plume has been dug out but nice “thunder eggs” can still be found.
Priday Plume Agates come in “thunder egg” formations. "Thunder eggs" are chalcedony filled masses that fill former cavities in volcanic rocks. The nodule formations are usually spherical in shape and look like ordinary rocks on the outside, but when cut have beautiful centers of agate or jasper. Priday Plume Agate “thunder eggs” are usually small, but the agates inside contain a wonderful assortment of colors and patterns. They are considered agates because they are often at least partly translucent.
As with most agates and jaspers, the “thunder eggs” can have very characteristic features to its origin. Priday Plume Agate is noted for its multi colors and bright filamentous plumes, as well as occasional “fan plumes” that are truly spectacular. The nodules are normally rather small, so they do not yield large volumes of material.
Native American legend reportedly considers the thunder egg rocks to be the eggs of the Thunderbirds which occupied Mount Hood and Mount Jefferson. It is said Thunder Spirits on the mountains hurled the "eggs" at each other.
On March 30, 1965, the “thunder egg” was designated as the Oregon state rock.
Priday Plume Agate cabochons are very intricate, partly translucent and take an excellent polish. They are perfect for your custom piece of jewelry!
Priday Plume Agate cabochons have protective properties and is said to give security, self-confidence and inner stability.