Chalcedony of Staritsa and ratovkite of Derzha 2022

4 years have passed, and again I was drawn to the Tver region - to the Staritsky quarry for milk quartz and chalcedony secretions. And at the same time behind the ratovkite (but this time I planned to visit its other point - on the Derzha River). Initially, I thought that I would not write a report - I already wrote about this deposit, but the result of the trip pleased me, which made me take up the pen. Sorry for the keyboard.

In short: my friend and I set out there on Saturday morning. Although this is a neighboring region, it takes me almost the same time to travel from the north of Moscow along the highway as to the Golutvinsky quarry, which is in the south of the Moscow region ... And about half past twelve we were already at the quarry. This time, knowing the local landscape, I immediately stopped at the back of the quarry, driving there along the Volga, which closely adjoins it. Although it would be possible to drive through the quarry - they don’t drive away from there. At least when industrial work is not being carried out there, and on weekends they are does not work.

There was nothing left on that wall of the quarry where I extracted the secretions last time. But on the opposite wall, there were signs of fresh excavator work. And where there are fresh outcrops, there are more chances ... Before we had time to examine this wall, an SUV and two cars drove into the quarry. This strained us - there might not be enough chances for everyone ... But it turned out that this was Mikhail, named "Passer-by", brought the children and their parents to show the quarry. He showed it to me too: "The largest quartz crystals are here," - Passerby led me to a pile of oversized blocks of rock. "Like this?" - I picked up from under his feet a druse of rather large, by Moscow standards, smoky quartz crystals with shiny edges. It is in the photo that he is so nice, but there he was covered in limestone ....

Large crystals are, of course, great, but oversized ones remained oversized because they were made of flint - you can’t break them. There are cavities, but there is no health on them, to split oversize. Therefore, we returned to the limestone side of the quarry.

Now about the fresh wall of the quarry. On it, as expected, there were vertical cavities in the limestone filled with secretions of chalcedony. But what caught my attention was the cavity the size of a head.

Putting that head in there, I saw that the cavity went deep into about a meter or more. One of its sides in many places was covered with druses of milky quartz crystals, and at the end of the cavity there was an accumulation of original chalcedony "flowers" (let's call them that) and again - druses of milky quartz. But at first glance, everything looked hopeless: at the entrance to the cavity, milky quartz rested on thin crusts of chalcedony, and when trying to separate them from the wall, milky quartz separated completely - crumbling into separate crystals. You can't get inside either - the arms are short.

But it's good that the limestone wall was broken by powerful cracks - it was possible to take out large blocks from it, expanding the entrance to the cavity to the width of the shoulders. Gradually I went to work with my head.

At the same time, the comrade stood on the lookout - he made sure that the upper plate did not begin to "breathe". Behind each block taken out, new tubes of chalcedony and chalcedony "flowers" were opened. Carefully breaking the limestone around them, we quarried them more or less intact.

In the broken thick secretions, there were crystals of milky quartz - as it should be in this quarry. Quite a number of intact secretion tubes completed on both sides have been obtained. On the heads of some of them were intergrowths of milky quartz crystals. But there were few large samples. We came close to the end of the cavity - another 10 centimeters - and I could touch the crystals and chalcedony flowers that had grown there - but the cracking of the blocks in the zone of the cavity ended, and we could not take out more blocks.

But even so we got it quite well: 2/3 of a twenty-liter canister. Milky quartz from Staritsa is not at all uncommon, but I have not seen "chalcedony flowers" except for my safe-collections. I'm sure I'm not alone in their prey, but still...

And then a crowd of people burst into the quarry - an excursion of Tver children-lovers of paleontology, led by a guide. Children began to recklessly "clean up" the quarry from brachiopods and etc. This aroused the curiosity of the parents accompanying them, who also joined the search. By this time we already wanted to leave, but we had to wait until the children were taken away from the quarry. Suddenly, someone will be interested in our hole in the board (they are such children…) - it was no need to the work of our hands to fall upon them.

When we were leaving the quarry, a stork flew low over us. Big .... With a red beak. We spent the night on the banks of the Volga. We got up at 7 am and after breakfast visited the quarry again. Maybe there is something else? Knocked out a couple of secretions from the walls, one of which was quite nice. And once again looked into yesterday's hole. The crystals didn't grow overnight. Climbed into it as deep as possible, and took a picture with a flash. Now you can see what the dwarves' cave looks like before a man got to it.

She is still there in this form. At least it was when we left.

Already at home, sorting out samples, I discovered hitherto unknown to me. It's no secret that many samples from Staritsa glow green under UV. No one seriously understood what causes this glow. Presumably opal-hyalite or the presence of uranilion (at a concentration that does not cause radioactivity). Therefore, the discovered green glow did not surprise me.

I also found that the enclosing limestone at 365 nm glows bright light brown. The color is the same as that of aragonite in UV. But limestone is composed of fragments of shells, which are composed of aragonite. So that didn't surprise me either. Then I found that several of the samples were glowing purple. Subsequently, a person engaged in optical research on minerals said that the chalcedony itself glows. More precisely, the reflection of the violet light of a UV lamp occurs due to the alternation of transparent and opaque particles of chalcedony.

Then the very last sample, knocked out of the side on the second day, fell into my hands - it contained both green and purple, and most importantly, a rich crimson color. And what's this crimson thing? The color is similar to corundum, but where does corundum come from in sedimentary rocks? Moreover, corundum glows at both 395 and 365 nm, while this sample at 395 did not glow at all. And not calcite. Calcite glows better at 395 than at 365, and this sample, as already mentioned, did not glow at all at 395 nm. Unfortunately, after etching in hydrochloric acid, only luminous red dots remained from the luminous red band. There is an assumption that this is an impurity of manganese.

And as soon as the conversation took a near-scientific turn, I must say that everything that I wrote above about the chalcedony from Staritsa is only relatively true. A couple of years ago I made laboratory section of it and sent it to Moscow State University for analysis. There opinions are divided:

Version 1: Pseudomorphosis of quartz by quartzine,

Version 2: Only chalcedony, silicified in places.

You can choose any option that you like best. In any case, these formations of such an unusual pimply and concentric shape are very picturesque and original.

I noticed that the silica secretions were located in the limestone layer under the flint layer. I would venture to suggest that the nature of their formation is as follows:

- flint is based on silica with the formula SiO2

- silica reacted with water to form silicic acid according to the well-known formula SiO2+2*H2O= H4SiO4+(SiO2){x-1}

- silicic acid, reacting with carbonates that make up limestone, corroding them, formed holes and remained on their bottom. Gradually, under the action of acid, the holes in the limestone turned into vertical cavities.

- silica from the silicon layer flowed down the walls of the cavities, forming secretions in the cavities.

If my assumption is correct, then in other manifestations of silica, collectible silica (for example, agate) should be sought under a layer of flint.

Of the samples found during this trip in Staritsa, I would like to draw the attention of the respectable public to three of them.

1. Fusion of two secretions with milky quartz crystals at the head of each. The fusion of secretions in the oxbow lake is a rather rare phenomenon, because vertical tube-cavities in which they are usually do not intersect. In addition, it is very problematic to get such an accretion intact. Until now, I have not seen the fusion of secretion tubes and, accordingly, have not mined. I'll keep it for my collection.

2. "Chalcedony flowers" on a fossilized mollusk. Rather, this is not a mollusk, but its internal imprint. The shell of the mollusk itself dissolved, leaving a cavity in the limestone massif where it was located. These "flowers" bloomed in it. I accidentally took a picture of this sample at the time of extraction.

But only at home I recognized a fossil in it.

3. Rosette of milky quartz on brown quartz. 2 sided sample. I'll keep it in my collection.

We return to the description of the trip itself.

The next point is a small abandoned quarry in the forest on the river Derzha. Convenient - almost on the way home. It describes fild of ratovkite. Ratovkit is limestone colored with fluorite. Four years ago, I was at another ratovkit deposit on the Vazuza River - I was not impressed. This time I was not impressed by this point. Although this is a novelty of the situation. I was hoping to get large pieces of ratovkite for stoun balls. But alas, the manifestation is very local, and the largest pieces are not the largest.

But this abandoned quarry turned out to be a funny place. It was equipped as an apiary - it had 17 cabinets with multi-tiered beehives.

And the quarry itself was very densely strewn with moose droppings. There were also moose tracks. You see, there are plenty of moose.

A lot of honey, a lot of moose - an ideal place for bears ... By the way, there are three thousand of them in the Tver region. But I digress.

We collected a box of ratovkit and embarked on the reverse course. Now it is necessary to acidify the limestone from chalcedonic (quartz?) secretions, so that they look good - I like their original outer surface and general pimply even more than the milky quartz crystals in them.

Samples for sale from this trip HERE

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