Accidental Discoveries: Unusual Salt Crystal Whiskers

January 09, 2017



January 2017 Viewer's ChoicePhotographers: Dave Lynch and Paul M. Adams
Summary Authors: Dave Lynch and Paul M. Adams

Patrick Manson, the eminent parasitologist, once told a colleague:

“A man may search for a shilling and find a sovereign. The important thing is to search.”

Much of science is built on accidental discoveries, and one such event happened to us a couple years ago. We were doing a survey of evaporite minerals in Imperial County, California, at a site where water was bubbling up out of the ground. The area was coated with deposits of minerals like halite (NaCl), gypsum (CaSO4 • H2O) and a number of interesting magnesium carbonates. We came across a small patch of white, fuzzy material that we thought was probably some kind of mold or fungus. This made sense because the area was wet. Expecting nothing too interesting, and almost as an afterthought, we collected a sample and moved on.

Back in the lab we put some of the fuzz in the scanning electron microscope (SEM) and took a look. What a surprise! It was not fungus at all but just plain old salt (halite) that had grown into long strings of microscopic cubic crystals. Note that for the scale on the top photo, 4 cm is about 1.5 inches; in the bottom photo, 50 microns is about 0.002 inches. To our knowledge, such whisker growth in salt has not been seen before.

It was a minor discovery to be sure, but Patrick Manson was right: “The important thing is to search.” And it’s a good reminder that our intuition and casual opinions can be wrong. As Mark Twain said: “Supposing is good, but finding out is better.”