Butterfly Quartz

What looks like two quartz rocks on the left, (9 o'clock) is really one, joined at the center, each the size of a man's fist. It is placed on a rock pile; the root of a Hemlock is working it's way over and in-between.
There is a 2nd constructed pile (below, )located about 1/2 mile away, with a similar  butterfly shaped quartz.