On Sat. April 20th we had a field trip to a private quarry near Biggs Junction, Oregon for Biggs Jasper and Agate. Jay Carlson of Sherman County Rocks in Rufus, OR, manages the operation and is doing field trips for rock clubs only. We had a beautiful clear day and started out by picking through the piles of material at his shop – Wascoite, Grainite, China Hollow, and Biggs Jasper/agate. Jay also has some beautiful finished material inside his shop. There were 20 people in 12 vehicles that went up to Beers Mtn. A few things I picked up from Jay’s explanation last year of the material is that it’s a mudstone formation formed millenia ago by thick mudpools under and over basalt lava flows. There were gas bubbles burping through the thick goo causing the intricate patterns to form as it was going through a hardening process. Bands of limonite (a type of iron) form the intricate patterns. It’s highly metamorphed and over time some agate and jasper formed in seams and pockets in the stone. The material takes a great polish. Mostly in brown tones, there are some hints of bluish and greenish coloration and pockets/seams of druzy crystal. The sites were easy to pick. A few people chiseled out chunks from the hard rock, but mostly it’s walking around and collecting loose material. The hardest part is deciding what to take home. The Beers Mtn material as well as the Wascoite and Grainite was $5/lb and the China Hollow material was $2/lb. We started out at 8:45 AM and finished by 12:00.
Afterwards some of us went to the Polka Dot Agate mine and others went to Richardson’s Rock Ranch. Both of those are about 80 miles further south via Hwy 97. At Polka Dot we chiseled beautiful blue agate from a large deposit that they’ve unearthed on the property. It’s very hard and dense and difficult to get chunks out, and one has to make a time slot reservation to work in the pit, but they also have a pile that you can pick from which is much easier.
Members who joined me were:
Scott & Laurie M., Christina L, John & Dave C. & friend Mike, Kari C., Scott M., Marion R., Michelle & Jerry M., Noelle B., Pete A., Jarrod D., Chris W. +2, Arlea W. +1.
Submitted by Roger Danneman Field Trip Guide
