Had no earthly idea what Liesegang banding was, but if Callan says it's the best, you know it's something good. So I clicked through. Do it. Go on.
Amazing, isn't it just? Made little lights go flash for me, because it turns out I've spent a lot of time surrounded by Liesegang banding. It's all over the sandstones in northern Arizona, and we used to sell bits of it in our bookstore, coasters and bookends and such. It's marketed as "picture sandstone." The patterns are gorgeous. When I saw stacks of coasters at the rock shop near Gingko Petrified Forest State Park, I had an acute onset of terminal nostalgia and bought some. Lovely!
|One o' mah coasters. Just look at that Liesegang Banding!|
In the meantime, we get to look at the pretty results. Imagine my delight when, in a Google search for Liesegang banding, I got led to none other than Brian Romans's very own blog, and this gorgeous field photo:
|Liesegang banding, Valley of Fire State Park, Nevada (© 2009 clasticdetritus.com)|
Then, after a great many years and a general dry-out, you get wildly-patterned formations like the above, and some bugger comes along to quarry them for things like this:
|Mah other coaster. I like the way the Liesegang banding resembles the dune fields the sandstone formed from.|
In nature, things aren't so neat as his concentric rings. Liesegang bands appear as, of course, bands, but also rings, spirals, and spheres, oriented in various directions, with younger sets cutting across and sometimes dissolving older ones.
One of the most fascinating things about these bands is that they're formed by a self-organizing process: they don't need a template for their patterns. They're not directed by something living. They just happen. All of that beautiful, artistic complexity is the result of simple, mindless processes. I find that enthralling. The power of physics, chemistry and geology to combine and form such patterns is amazing.
Wonderful ol' world, innit?
"Liesegang pattern development in carbonating traditional lime mortars." Rodriguez-Navarro et al, Proceedings of the Royal Society, 2002
"A short history of 'Liesegang rings.'" In Silico Ltd.