I have a big chunk of cinnabar. Now what?

Miscellaneous and Personal Stuff I Must Share
1

Years ago, we were hiking on a trail in the mountains in Santa Clara County. We came across some pretty red rocks, and I took a chunk home with me. It’s about the size of a large man’s fist.

My hometown has always talked about how poppy jasper is to be found nearby, so I always thought this rock was poppy jasper. However, for some reason I followed a link the other day and saw a chunk of rock that looked exactly identical to what I had. It’s cinnabar, from which mercury might perhaps be extracted. Cinnabar is another mineral to be found in Santa Clara County, and in fact was mined in the hills years ago, near New Almaden.

This rock has sat as a mostly untouched curiosity on my desk at work for years. It’s a nice shade of muted red, and it looks more like a piece of raw chuck roast than a rock. Is it dangerous to handle it? Is it valuable to a rock collector?

2

If it’s just going to sit on your desk, it won’t be a problem. The toxicity can be released by trying to get the mercury from the stone so no problem there. I don’t know the value to rock collectors but many jewelers stopped using it rather than risk being around the dust. And don’t store it in a hot place.

Perhaps donate it to a museum of natural history?

3

Just be careful not to confuse it for a large chunk of a cinnamon bar. The Venn Diagram for their respective uses has little overlap.

4

Googling suggests that problems are related to eating cinnabar or inhaling its dust. Hazards from handling should be low provided you then wash your hands before eating.

It would be a very bad idea to heat it, or let children play with it.

5

Sell it to Cinnabon?

6

When I was a kid I had a book called “Cinnabar, The One O’Clock Fox”. Loved that book.

7

From the Wikipedia page on Cinnabar

So very much what carnut was saying, except that trying to use it in art or coloring or something, even without trying to separate the pure mercury, could lead to bad consequences. so don’t handle it too much. But sitting on your shelf it ought to be fine.

There’s also this

so don’t eat it. Even a little bit

8

My piece looks almost exactly like that piece in the Wikipedia photo, CalMeacham. Those articles alarm me and I think I’m going to toss it. I don’t want to end up dying from mercury poisoning, like Louisa May Alcott.

It’s a shame, though. It’s a handsome piece of rock and it has a flat side which makes it an ideal paperweight.

9

That seems unlikely. She was dosed with a mercury compound, and unless you’re gnawing on your sample, you oughtn’t to be ingesting it. (And apparently some now think that she might have had an autoimmune disease, not mercury poisoning).

But you could always put it in a sealed see-through case, or even coat it with a transparent coating. No need to throw it out.

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That’s what I was wondering about. Plastic display case, or even coating with acrylic (though it discolors after a while).

11

If you encase it in resin it would prevent accidentally mercury exposure but would still look like a pretty rock and still make a great paperweight.

12

I think you should carve it into the shape of a pine cone.

Then you would have a cinnabar pine cone.

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It’s interesting that the place you found it is called New Almaden. Almadén, in Ciudad Real, Spain, has the biggest mercury deposits in the world and was exploited already by the ancient Romans. 250.000 metric tons of mercury have been extracted so far, according to Wikipedia, but the mines were closed 2002 due to the toxicity of mercury. There are no mercury mines left in Europe, it seems, but those in Almadén are now a tourist attraction.
The mines in Santa Clara County must be quite old if they have this Spanish names related to mercury’s history.
I would keep it. You have had it so long and it has not killed you yet, you seem to be handling it correctly. Just don’t lick it and don’t use it to colour your goulash, bortsch or paella.

14

Instead of tossing it, get a lucite box for it and seal it into it, or perhaps coat it with polyeurethane

15

Could be other minerals as well. Iron oxide colors many rocks red. Cinnibar’s hardness is very low(2-2.5) so a simple scratch test might help identify it, Or just take it to a local college for ID?
Grinding and sanding rocks and minerals is where most of the hazard lies. (long time rockhound here)
“I brake for rocks”

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Yep, New Almaden is named after the Almaden in Spain, and there was a huge mining community built around our local Almaden. There was (and still is) a town and a big community building and hotel to house the miners. It was all built on cinnabar, which mineral was used in helping to process the gold which was mined in the Sierras back then.

They mined cinnabar so vigorously that lakes and streams near the area have warning signs posted on them to let you know that the water is tainted with mercury and not to drink it nor to eat fish caught there.

I found my rock in hills not five miles or so from the town of New Almaden, so Occam’s Razor says it’s cinnabar.

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Yes I think you are correct. Occams Rocks!
We have abandoned mercury mines down here through the central coast as well. I’ve visited one or two, really toxic areas. Including one just over the hill from Santa Barbara
The mine workings are interesting to observe, and the discarded rock dumps often have colorful specimens.