Black Sand and Manganese – A Cave Pigment Expedition

– Were you scared?
– Of course I was. But admitting it? That would be a shame.
– What were you afraid of? You’ve hiked all over the mountains, caves included.
– Yeah, but I’ve seen those speleology videos—crawling through mud, squeezing through rock crevices…
I’d never done that before. And honestly, I was scared.

Black sand and manganese were the reason I ended up in that cave. A few days have passed, and we’re already planning the next trip.

If you want to speed up the drying of oil paint, you go to the store for a siccative—a chemical stink bomb plastered with warning labels. But if you look deeper, you’ll discover a quieter, older solution: manganese-based pigments.

The old masters knew this. They relied heavily on brown underpaintings, especially in works left unfinished. Natural umber, burnt umber, and other earths rich in manganese did more than provide tone—they helped →oil paint dry faster.

All it takes is grinding umber and leaving it for two or three days. Boom—underpainting dry.

When I first thought about making pigments from scratch, manganese was at the top of my list. So when I got a tip that there might be some in a cave nearby, I didn’t wait long.

At first, I stood at the entrance of →Nietoperzowa Cave, planning to ask a geologist about the black stuff visible near the walls. But then curiosity kicked in.

I followed the geologist into a narrow recess deep inside. We crawled through mud and shadows into a pocket of the cave filled with black sand—dark, heavy, and unmistakably rich in manganese.

I remember the panting and scraping of my boots. I asked myself if all this discomfort was worth it. The answer came without hesitation: of course it was.

Because after drying, sifting, and grinding that black sand, I ended up with something extraordinary—a sepia-toned glazing pigment that dried in under twenty hours. No chemical stink. No additives. Just black sand and manganese, working together like they did centuries ago.

Once dry, the pigment went straight into a jar. The label reads simply:
MANGANESE / NIETOPERZOWA CAVE.