I am very happy to report that Great Lakes Renewable Energy/Lumber Jack pellets was EXTREMELY quick to respond!
I talked with Chrissy, and she quickly forwarded the info and pics to the plant manager who very quickly identified exactly what this was. Believe it or not it was NOT a rock (even though it looks and feels exaclty like one).
She called me back and asked me to see if I could easily break it in half, which it did, and sure enough it broke and the edges crumbled into super fine wood dust. WOW, I'm telling you that thing looked and felt like a piece of rock!
Every now and then, during maintenance, they have to clean these compressed wood dust deposits out the chutes. A piece somehow got past their screening process, which is suppose to catch anything extraneous, and ended up in my bag of pellets. Chances are, had it gotten into my auger tube, it would have simply sheared off into smaller pieces and simply burned along with the pellets.
They were extremely grateful for calling and sending them the pics, and they are going to review their screening process to make sure this doesn't happen again. They are also sending be a new 40lb bag of pellets to replace the bag this came from.
I can happily give a two thumbs up for Lumber Jack's top notch Customer service,
and will continue buying their products!
Cliff