this is either limestone or quartzite. You can see the animal spiraled down and around. The hole on the side of the rock is part of the spiral and the tail is exposed. The entire negative of the fossil is lined with the tiny quartz crystals.
This was near the pink and grey quartzite that I want to try to polish, but not the same. 
I am still looking for the pretty quartzite  in the many many boxes labeled "rocks" ... I started labeling the boxes "mineral specimens" so the movers wouldn't throw them around.  You should have seen their faces moving boxes of "rocks"..one young kid actually walked off the job.

Thanks for the reply Dennis. Very informative. Thanks.