Imperial Jasper is considered to be one of the five fine jaspers. (The other fine jaspers are Bruneau jasper, Morrisonite, Willow Creek jasper and Blue Mountain jasper). Imperial Jasper is found about 50 miles northwest of Guadalajara, Mexico on the east side of a steep canyon. This canyon lies north of the small town of San Cristobal and its steep slopes are covered with dense vegetation. The jasper-bearing area is very large, almost 6 km long with many individual deposits, each with its own characteristics. Pink Imperial, Brown Imperial, Green Imperial, Spiderweb Imperial, Select Imperial, and Royal Imperial are all names associated with these various jasper deposits.
The jasper occurs as veins, large filled vugs, and as nodules in the host rock. Pieces over 100 lbs. in size have been recovered, but due to extensive natural cracking in the deposit most material is much smaller.
The deposits are also rich and concentrated. In the last decade over 100 tons of Imperial Jasper has been mined. Most of the deposits are under claim, but the claim rights are complicated by multiple land owners. The amount of jasper produced from this area far exceeds the total lifetime production of all the other fine jaspers listed above.
Royal Imperial Jasper
Royal Imperial Jasper is found primarily in a side canyon over the ridge to the east of the other Imperial Jasper deposits. It is somewhat different in that it is formed entirely as nodules. The nodules are generally small and flat in size (about 2"), and have a smooth, soft white or orangish chalky outside. The Royal Imperial Jasper is known for having a high percentage of the “egg” pattern associated with these types of jasper. The egg pattern does not form in the process of the formation of the host rock, but in the process of the formation of the jasper. Not all Imperial jasper displays this egg pattern, but most of the Royal Imperial variety does. What makes this deposit so unusual is that it is the finest, largest deposit with egg patterning known in the world to date.