Land of Extinct Volcanoes part 11/16 - Septarians of Nowy Kościół

Septarian resembles solidified (usually calcified) dry mud. While the actual process of their forming is not fully known, I imagine this is the future septarian field:

_{Dried floor of Zerówka}

All it takes is for a calcium carbonate from nearby pile of quarry rubble to be dissolved and washed in the cracks to form calcite, then some pressure, maybe some heat, and we got new septarians :o)

In order to find septarians I've made another appointment with Mr. Piotr Sarul. We came together with a mineral hunter from France with his Colombian spouse. Not very far from the workshop (but I was obliged not to share exact location) we reached a set of holes on the side of the forest trail. Holes like this one:

The floor is littered with crushed marlstone - a soft rock that resembles chocolate that was freshly taken out of fridge (in color, texture and hardness). When in contact with water (or sweat) it dissolves into highly staining red mud.

The job was to pick through the marlstone at the very bottom of the hole - septarians can be found in couple of layers, but the ones in the three top ones are mostly of low quality. Even though the rock is soft, the work is not so easy. Once your pickaxe (or claw hammer in my case) bounces off of something hard, you have a hit, and the actual work starts.

_{My small gardening spade was surprisingly effective as a substitute for chisel - the actual chisel worked way worse in this soft rock.}

You need to scrape all the rock around your find, otherwise it won't come out, even if it looks like it already should.

That day I got myself three specimens, all were cut but I only polished one.

Once you remove and wash all the marl from the outside of the nodule, the calcite veins are clearly visible.

I went back to the place the other day. Someone worked there earlier as well, because the hole was deepened to the point where it became unsafe to dig further. Pieces of rock were falling from the overhang, so before I could start my search, I had to break them off first and then clean the floor (thankfully I took a bigger shovel with me that day). At first I was unlucky, tried to dig even deeper, but I found nothing. I even took one small septarian from upper layer, just as a consolation prize. Finally I decided to dig in the center, where the hole was most shallow due to the thicker root of nearby tree that was hindering the movement. Tried to cut it off with bear-claw neck knife I always have with me, but it would take too much time (the tree itself was couple of meters away, no risk of it falling over). Instead I decided to dig in horizontal position, under the root. Turned out to be a good idea. After a while I got a hit. This one was big. I was digging and digging and digging... Forest was getting darker and I couldn't pull the stone out. Earlier I asked if it is possible that someone would find a septarian and leave it in the rock - never happens. It looked like I would be the first to do that.

But persistence paid off. Phew... Later I weighed the specimen - 11.5kg. I had to make another appointment with Mr.Sarul so he would cut it for me. It was pretty hard to cut even with the biggest cutting disc, the marks are still clearly visible on the stone.

_{(yeah, yeah, grinding and polishing, when do I find time for that...)}

My consolation prize was also cut - doesn't have the colors nor the calcite veins and crystals, but I think it is still pretty ok.

Most septarians on the market come from Madagascar. They have nicely developed yellow calcite parts but the "mud" part is grey or grey/brown like in my specimens. Mr.Sarul had some completely different septarians from unspecified place in Germany. I've never seen one in such colors before - the main body in distinct yellow, while the cracks were filled with small, darker crystals. I wonder if I can find one like that to buy on some mineral show...