The Richardson Rock Ranch near to Madras is one of the most popular origins for “thundereggs” in North-America. This location was formerly known as the Priday Ranch.

The Warm Springs Indians have been given credit for originating the name “thunderegg” to this spherical rocks that are including often starshaped blue agates. They tell that two high Mountains - today known as the Mt. Jefferson and the Mt Hood - would at times become angry with one another. During the disputes, accompanied with thunder, they would hurl these spherical rocks at each other. Stray shots would land over in the tribal reservation, hence the Indian name of “thunderegg”. At the Priday Ranch it was possible to collect these “thundereggs against paying a small fee in the 1960ies. Today they were mined by the owner. However - a lot of these marbles are reaching the collectors market to reasonable prices.

Typically for these “thundereggs” are the reddis to brownish colorization of the matrix surrounding the agate in the core. The agates in the center of these lithophysae (scientific name for “thunderegg”) are more or less strarshaped. Other colours than blue or grayish are rare at this location. Sometimes the “thundereggs” are hollow - only showing a thin rim of chalcedony.Agates of the gravitational typus (“water-level-agates”) are quite common at this place. The pattern of this type of agates is depending on the cut: It is showing a fine striation if the cut is 90° degrees to the layers, and it is showing a mor cloudy appearance if the cut is parallel to the layers.

This worldfamous agate-finding location is offering several so called “beds” of distinctive agate-occurences:

- the blue bed (this page)

- the red bed

- the moss bed

- the flowerbasket

- the flat bed

- and the polka dot agate occurence