Way, way, way in the back of the Payson Rimstones Rock Club’s Gem and Mineral Show in a side room in a black box with a weird light waited The Secret of the Universe.
I almost missed it, wandering agog past the bins of malachite and azurite and pyrite and magnetite and fluorite.
I had lingered over the 60-million-year-old dinosaur droppings and the 40-million-year-old shark’s teeth and the chambered spirals of the ammonites — which ruled the seas 400 million years ago before falling into darkness.
So I had stayed already longer than I had intended, with all the history of the Earth lined up on shelves. I can trudge bored and bemused through any mall, wondering at how the stores stay in business with so much useless stuff on sale. But set me loose in a good gem and mineral show and I turn into a shopaholic hoarder.
Still, I did not expect to fall so violently in love.
But then I came upon the fluorescent minerals, tucked away in a box facing the wall. Inside the black-painted box, a carefully mounted short wavelength ultraviolet light beamed invisibly down on the Rosetta Stones of the Universe.
Unsuspecting, I peered at the brightly glowing rocks, purple and violet and red and orange and green — all lurid as a schizophrenic painter’s hallucination.
Lynne Wheeler-Benker bustled about proudly, showing off her obsession. She had gathered the stones over many years. Sometimes, she inched across jumbled slopes near the tailings of lead and uranium mines in the dark of the night, casting out ahead of herself the invisible beam of her UV light. Sometimes, she wandered the sun-bleached slopes with a black cloth under which she could huddle to examine a likely looking rock.
I was instantly smitten. Although I have seen fluorescent rocks often enough before, something about this covert, unexpected and miraculous display coupled with Lynne’s burbling of enthusiasm snatched my breath away.
Turns out, fluorescent rocks offer a skeleton key to some of the great mysteries of the universe, knitting together chemistry, geology, cosmology, quantum physics and scorpions.
Anywhere you start in an effort to explain why these normally inconspicuous rocks glow in UV light reveals the inner workings of the universe.
So, start with a certain kind of rock — calcite, diamonds, halite, opals, quartz, zircon, scheelite, gypsum or any of a dozen or so others. Mostly — they won’t glow when bombarded with UV light. But if an “activator” mineral gets mixed in to the composition of the stone, anything can happen.
Such activator minerals include manganese, uranium, manganese, sulfur, tungsten, molybdenum, chromium, nitrogen and others.
Harking back to basic high school physics, you may remember that atoms have a nucleus of neutrons and protons surrounded by shells of electrons. The electrons orbit the nucleus furiously, occupying certain energy levels. The electrons can absorb energy that bombards the atom, shifting their energy states.
Now, throw in some ultraviolet light, a wavelength of light our eyeballs can’t detect. This brings us to photons, bizarre energy creatures stranger than our minds can readily grasp. Mostly, we think of photons as light. Sometimes, photons act like little speeding particles without mass — which is itself a ridiculous statement. Sometimes, they act like radio waves — an energy wave with a distinct wavelength. They express some essential law of the universe — since nothing can go faster than a photon. Once you reach the 186,000 mile-per-second velocity of a photon on a tear, time stands still — so you can’t speed up any more.
But never mind that — let us return to glow-in-the-dark rocks.
When photons in the ultraviolet range fall upon these seemingly ordinary rocks, a very strange thing happens. The mineral’s electrons get all excited, absorbing the photons. But the electrons can only hold onto this captured photon for no more than 20 billionths of a second at most. Then the electron spits back out the extra energy. Here’s where the activators play their role. They catch the emitted photon, go through their own absorption and release — and end up unleashing a photon undulating along at a frequency we actually can see.
And what a sight, this lurid glow in the darkness.
There, see the orange-red glow of halite with a dash of manganese.
Here savor the green pallor of autunite with a trace of uranium.
Over there study the yellow glower of scapolite with a trace of sulfur.
Lynn provided a two-page description that listed the possibilities. Some minerals almost always fluoresce, including scheelite, autunite and hydrozincite. Some only glow with the right mix of activators — like calcite, barite, gypsum, apatite and diamonds.
Like the true love or the peculiarities of your offspring, glow-in-the-dark rocks offer a miraculous blend of possibilities.
So I stood and stared until my brain fairly glowed in the dark.
Then I thought about scorpions (bet you thought I had forgotten about scorpions).
See, scorpions glow blue-green in the dark when you bathe them in ultraviolet light, as though they’ve been eating scheelite with a chaser of tungsten. Scariest thing that my youngest son Noah ever said to me was that one night he had a dream about flying scorpions. You can’t kill a scorpion with a shovel — you need an actual jackhammer.
Anyhow, no one knows why the nocturnal scorpions glow under the beam of a UV light.
One theory proposed by University of Oklahoma researcher Douglas Gaffin suggested the UV glow enables the scorpion to use its whole body as a light sensor — which helps it quickly find shadows to hide in, even at night in the moonlight.
Another theory advanced by California State University expert Carl Klooch suggested the fluorescence of a scorpion might help them detect UV light bouncing off the moon. Scorpions avoid coming out into the light of a full moon, probably because they have better success hunting in the complete dark.
Electrons, photons, minerals — scorpions: I left with my head buzzing — every one of my neurons in an excited state.