The coral is all the same basic shape / look. This makes it easy when trying to locate them on the floor. One thing I've noticed is that they seem to spawn more on the snow vs the ice. And the times I've seen them spawn on the ice, it was more closer to the snow then say, dead center of the frozen pool of water.
the other thing that is a bit annoying is that you can't click the item then the coral. You have to click the coral then the item.
I've attached an additional screenshot, to go along with what's already there. This one is zoomed in on the coral.