Martian Selenite

When calcium and sulfur get together with water, a chemical called calcium sulfate can be formed. It happens all the time on Earth, and we call it gypsum. Gem collectors also call it selenite.

I was visiting the big greenhouse at Gordo Station to pick up a recent harvest of green beans when I spotted a bowl full of square, white crystals.

"What is this?" I asked the farmer. I picked up a crystal and looked closer.

She wiped her hands and came over. "That's selenite. Just got a fresh batch from Oppy Station. I traded the prospector a kilo of radishes."

"It's pretty," I said.

"Some folks Earthside think it's good for cleansing your energies or overcoming anxiety. Or something like that." She rolled her eyes as she said it.

"What do you use it for?"

"Fertilizer."

I must have looked confused.

"Yep. We grind it up and add it to the Mars dirt to displace metals and other chemical salts. It stimulates soil health by removing iron and aluminum toxicity barriers.  So, I guess it cleanses our dirt's energies!"

I placed the crystal back in the bowl. "Where can I find some? My abuela's birthday is coming soon, and she loves this kind of stuff."

"You can take that one with you," the farmer said with a grin. "Tell her it'll cleanse her energies."

"Thanks," I said and tucked it into my arm pocket. I left with a crate of beans and a new interest in Martian crystals.