Science. Communication. Community.
Summer is wrapping up, and many folks are trying to squeeze in one last vacation. Here’s what a glittery beach getaway in California taught me about mineralogy, paranoia, and relaxation.
Last month, I took a short weekend trip to Coronado, California: a resort city and island just a stone’s throw away from San Diego. As I walked down to the beach, a relaxed vacationer, I was thrilled to see the sun, sand, and waves before me. However, as I got closer to the water, I was horrified: the beach was shining, and the waves looked as if they had been contaminated with some kind of glittering metal powder.
The glitter swooshed around in the water like a snow globe, and the metallic flecks, which were softer and flatter than regular sand, stuck to my skin when I stepped out of the waves. Instead of enjoying some beachside R&R, I found myself panicking.
“Was there an industrial accident? Is some unscrupulous company dumping metal filings into the ocean? The Naval base is nearby–is this some kind of experiment? There are children playing here–how do their parents not see this horrible glitter?” I thought.
Well, there’s a reason you haven’t seen or heard about this death-by-glitter scenario in the national news: that glitter occurs naturally.
A Google search revealed that those shiny flecks are actually a mineral called mica–the same type of mineral used to produce glittery substances prized by cave painters (40,000 years ago), cosmetic companies (1960s), and David Bowie as Ziggy Stardust (1972).
And under the right set of conditions, mica can end up in beach sands near you. In her book, Coronado, author Leslie Hubbard Crawford attributes the gold and silver specks to naturally occuring mica deposits in mountains over the Mexican border. The mica was washed down the mountains by the Tijuana River, which eventually empties into the Pacific Ocean. From there, the shiny mineral was deposited onto my beach by the Silver Strand littoral current–the same current that provides sand to many popular beaches in the region, from Point Loma, California to Ensenada, Mexico.
I was still suspicious. I mean, I knew that currents were strong, but why wouldn’t the majority of these tiny mineral flecks just diffuse out into the ocean?
It doesn’t take much mica to make a beach sparkle, says beach conservation website coastalcare.org. Thanks to a sheet-like atomic arrangement, specks of mica end up being lightweight and flat, meaning that they’re easily washed away by waves. However, the shiny flat flakes act like millions of tiny mirrors thrown into the sand, and are so reflective in the sunlight that they are visible even when mica accounts for less than one percent of the sand grains on a beach, the site says.
And as it turns out, people love these sparkly beaches (though they’re more affectionately known locally as “sugar sands”). In fact, based on a number of criteria, the very beach I visited was chosen as last year’s #1 beach in America by Stephen “Dr. Beach” Leatherman, Professor and Director of the Laboratory for Coastal Research at Florida International University.
So there I was, lucky enough to be on vacation, in the sunshine, at one of the top beaches in the nation–and I was panicking about an unnecessary scare. But I hope you can learn something from my pointless paranoia: whether you’re a scientist, a journalist, or neither, please don’t be afraid to enjoy our planet, responsibly. Skepticism is an important attribute–but it’s also OK to sometimes just enjoy the honest beauty of a sunset at the beach.