Helictites, for those who don't know (which included me until I read this article), are eccentric crystallographic formations (yeah, I know, big help). This means that instead of forming vertically like stalactites and stalagmites, the crystals form in gravity-defying directions and shapes. They are very cool to look at:
(image taken from the CBC article)
So have a look. It's just plain neat, in a geological kind of way.