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Let's Rock => Rock Talk => Topic started by: John Robinson on August 27, 2017, 12:11:43 AM

Title: Sorting agates and petrified wood
Post by: John Robinson on August 27, 2017, 12:11:43 AM
I have about twenty gallons of agates and bits of petrified wood I have picked over the years around the farm. It is habit-  I see a rock, pick it up put in my pocket then throw in a bucket when I get back to the house.
I was wondering if there was a quick way of sorting through these to find those rocks that would be worth cutting and polishing? Just grinding a bit off would seem like the thing to do(?)
Title: Re: Sorting agates and petrified wood
Post by: peruano on August 27, 2017, 05:48:06 AM
After you cut a few (hundred, dozens, or ??) you will learn to guess which will be pretty when cut without windowing or sampling. Of course you always could be wrong which keeps the game interesting as well.  When it comes to petrified wood, its relevant to determine, is it cracked, can you see evidence of the bark, growth rings, or other growth features, and of course color and contrasting colors. Some will surprise you but most can be predicted.  Agates are distinct beast set, but also judged on being solid, nice colors, and evidence of inclusions.  Cut into them all, but its still fun to pick the best first and start with it.  Its like Christmas everyday when you are sawing rocks.