Spathites are a variant of soda straws that are formed from aragonite, rather than calcite, and differences in the crystal structure of these two minerals create a different morphology. Instead of a simple tube like a soda straw, the spathite is comprised of a series of fan-shaped cones that occur singly or multiply, with the top of each new cone growing from the base of the one above, producing a stairstep-like effect. In soda staws the crystals of calcite are parallel to the vertical walls of the tube, whereas in spathites the crystals are at a 60-degree angle to the tube. The cones of the growing spathite enlarge in width until they exceed the width of a water drop and then the drops flow to one side, creating a new cone.

Spathites are rare in general but can be abundant in the caves where they occur. Some of the images on this page are from a large cave in Missouri, while the longer ones are from the tropics, where formations in general tend to grow larger.

AUTHOR: Dave Bunnell