So as part of my experimental farm I have been researching about how rock dust improves soil and mineral content. So instead of buying a bag of rock dust I went to my local hardware store and instead bought a bag of red lava rock. Now these rocks where to big so I used a sledge hammer and broke if up as small as I could. Before I could pick up the pieces my flock literally swarmed the shattered rocks and started swallowing them, leaving only the larger pieces. Figuring it'll help them just like the oyster shells do I decided to let them have a bowl of crushed rocks and sprinkled the rest over my garden. A week latter I've noticed several changes, first my most aggressive rooster was no longer fighty with me or the other roosters, my flock had alot more energy then usual even through the heat, and finally the eggs, the shell was extremely thick but when I finally cracked it open and cooked it the flavor was indescribably amazing and fulfilling. I believe that my flock may have gotten an extra boost if the trace mineral found in the lava rocks that is known to produce bigger, hardier plants as well. This is just an observation but I encourage anyone to try it out, even with other types of rocks as well.