Back in the early 60's my folks bought this place on the edge of town, (Monroe, MI). It had a nice garden spot out behind the garage. My Dad plowed the garden with his little ford tractor and while plowing, he hit a rock. When he stopped to look, there was a flat rock about the size of a platter. Got a shovel and started digging it out. Well, when he got down to about 1 ft. and now it was about the size of a card table. Now my dad was never a quitter, so he called a friend with a back hoe to come over and help him dig out a rock. When they got down to about 8ft. deep, they still haden't found the widest part. What they had exposed measured about 12'X18', it was clear that they wern't going to dig it out, so my dad went to the hardware store and a bought few sticks of dynamite, (it was the early 60's, all you had to do was fill out some papers and show a valid id). Now my dad was an experianced dynamite user so he was sure he could bust it up. He drilled a hole down under the rock and packed in several sticks of dynamite and touched it off. Now this rock was blue granite and was very hard. When the dust cleared, the rock had split vertically in 2 pieces with the smaller piece being potato shaped and about 4'x6'x 8'. Worse, the big piece had lifted out of the ground on the broken end and was about 2' above ground level. Finally, the contractor went and got a big bulldozer and dug a ramp down to the piece and dragged it out of the hole. He then backed the backhoe down the ramp and dug all the dirt he could reach from under the big piece. He was able to tip the big piece into the hole so that the top was about 3' below ground level. My mom decided that the small piece would look nice in the far corner of the backyard so they pushed it over with the dozer and it is still there. This all happened while I was in Calif. so all I have is my mom telling me what happened and my brother adding the technical details. My dad didn't want to talk about it for some reason. I have pictures around somewhere of the rock.
So, Pablo. Be careful about digging out that rock..