Here are some before and after pictures of the rocks that we have worked in the School of Hard Rocks. These rocks are all from The Rock Shed in Keystone, South Dakota. They have been a lot of fun to process and even more fun to share. Where it makes sense, you can see some "inprocess photos". Enjoy.
Blue Grey Agate
Changing the scale of the project - or - why I love my B1A1 tumbler.
I was able to combine all the rocks from my spring projects into a single batch in the B1A1 rock tumbler. Here is what they look like after 264 hours of grinding. I added in some pieces of rose quartz and some other rocks for my study on grind rate. I'll tell you now, I am seeing 4% reduction in weight per day of grinding. That is with either 90 grit or 220 grit abrasive.
I started tumbling 30 pounds of agate from Brazil today. These are nice big pieces and it will test my patience to wait for them to grind and polish. Charles Dickens would be proud - as you can see in the photo below, I have "Great Expectations".
Agate from Brazil
Most of the Brazilian agates are still in process. A few of the smaller ones are finished. They look a lot like chocolate.
Here are the agates after one grinding cycle. I really like the colors and the patterns that are emerging.