Thursday, December 1, 2011

Aurichalcite - It falls apart and is really frustrating and I hate it.

Well, we've covered quite a few basic minerals and opened our eyes to the possibilities that abound in the world of geology. I think we are ready for the some of the meatier secondary minerals that no one cares about. And so, without any further introduction, here is today's mineral.

Now, a lot of people will try to tell you that in order to learn about something, you need to learn a lot of fancy facts about that something. That's mostly true. Well, alright, that's all the way true. But what about if we have a bunch of opinions about that thing as well? Are opinions any less important than facts? Technically yes. But I'm going to tell you my opinions about aurichalcite anyway.

Aurichalcite is a huge pain in the butt. Here's why;

OPINION/FACT 1 - It never shows up in a convinent place.

OPINION/FACT 2 - It falls apart faster than grandma's bones.

I would have preferred that picture say “aurichalcite” instead of “dreams”, but when you’re stealing stuff off the internet you can’t be choosey. Plus maybe it’s our dream to find aurichalcite, then it totally works. Things that fall apart easily are the worst. Once in elementary school I made this really cool hat for "make a cool hat and wear it to school" day. Man, that hat had everything. A pocket for band-aids, two or three safety pins, a little blinking light at the top, everything a man could want in a hat. Anyway, it fell apart right before I got to school and I was totally the laughing stock of the class. Or would have been if I had been popular enough to warrent some level of attention. Sometimes flying under the radar is the best way to survivie kids!

OPINION/FACT #3 - Aurichalcite is haunted.

Nope, made that one up.

OPINION/FACT #4 – Now here's the kicker. Aurichalcite is really awesome. There really isn’t a photo to go with this one.

Now, again, those things are just my opinions. So you can see that I’m pretty torn on the issue. The title of this post clearly states that I hate aurichalcite, yet OPINION/FACT #4 states quite ot opposite. The only thing worse than having conflicting opinions about a mineral is having an opinion about a mineral in the first place.

Anyway, let's move on. For you hard-core “I want to actually learn something” types (nerds), let’s get into the nitty-gritty. But first let’s look at this cool bottle I found!

I don’t know what’s in it, but I’m guessing that it’s about 120 years old! It could be whiskey! Or some sort of whiskey-based medical juice! Anyway, if you are going to be a geologist, you need to keep your eyes out for other neat artifacts when in the field. With any luck you too could find an old bottle filled with some toxic liquid.

Let’s take a look at some other pieces of aurichalcite.

The first thing that jumps out at us is that, it looks like fuzzy blue stuff. When a mineral forms as a bunch of fuzzy little needles like that, it’s known as having a acicular habit. Neat! If you are anything like me, then your first thought would be that it was formed thusly…

Sadly, no. Muppets play little to no part in the formation of aurichalcite. Yet. In order to make aurichalcite, you need five atoms of zinc…

Another five atoms of copper…

And a gob of carbon, oxygen and hydrogen.

Bake them together and you get (Zn, Cu)5 (CO3)2 (OH)6 , or in otherwords…this…


Aurichalcite is an example of a "Pearly" luster folks! Have we talked about luster before? Seems like we have. Go read all the other posts and tell me if I've never talked about luster. DO IT!


Remember azurite and malachite? They also feature the CO3 and OH guys. As a result these minerals are all included in the same family of minerals known as carbonates. Pour a little hydrochloric acid on these buggers and stand back! Actually you don’t have to. They just fizz a little. Neat to watch though. Remember to ask your parents before you mess around with the family hydrochloric acid reserves.

Now before you run off with your picks and shovels to find some of this admittedly cool looking mineral, remember my second opinion of aurichalcite. It is incredibly hard to keep in one piece. This is due to a whopping hardness of 1.5. This pretty much means that a stern look will cause it to blow up.

Not only that, but aurichalcite has a “brittle” tenacity. This means pretty much what you think it does. Tenacity is a measure of a mineral’s ability to deform under some sort of impact. Minerals that are brittle don’t deform much. They just turn to dust. Like a mummy playing catcher for a major-league baseball team.

So we start to get a picture of why collecting the stuff is a challenge. You have to break off a big piece of rock and just hope that some of it survives. And it never does.

So other than the sheer thrill of hunting geology’s most structurally inept mineral, why would anyone want the stuff? Well, like anything that contains copper, it can be used as an ore of….copper. It clocks in at 14.5% copper, which means that if you had 100 pounds of it, you could make 14.5 pounds of pure-copper pennies. That’s as scientific as I’m going to get. Also that may be wrong. I’m not doing a lot of fact-checking here. Anyway, that’s not all that great. But where does the zinc content come in at?? Wait for it…

44.8 Percent! That’s pretty good. So it’s an even better ore of zinc, which we apparently mostly use for making little piles of white powder.

A final aspect to consider while pondering the uses of aurichalcite is by realizing that it is a secondary mineral. Have I ever described what that means? I think I have, but I don’t even know what day it is, so who can tell. Anyway, when an ore body is forming, the initial minerals to show up are usually known as the primary minerals. These tend to be somewhat simple chemically (but also sometimes not). Later groundwater shows up and messes with the primary minerals (using such processes as oxidation, which involves a bunch of fancy words to describe). This messing-with results in the creation of the secondary minerals, which usually are a little more colorful from a chemical aspect. SO WHY SHOULD WE CARE??? Well, if you are a miner and you find a bunch of secondary minerals, it stands to reason that there will be a bunch of primary minerals still hanging out somewhere, and those usually have valuable stuff in them. If you are anyone else, you probably shouldn’t care at all.

Let’s delve into history a little bit now. After all, this blog has the word history right in the title. Seems like I’m obligated. Aurichalcite was first described back in the good old year of 1839 by some fellow named Bottger. No one seems to remember his first name though. Geology can be cruel as well as kind. Anyway, this Bottger fellow gave the blue-green mineral the name aurichalcite (“mountain copper”), which was close to the name that ancient Greeks gave to brass. Brass is made out of zinc and copper. Aurichalcite is made out of zinc and copper. You should be able figure out the rest.

They’re both made out of zinc and copper. There. I helped out the slower of our viewers.

So, there, we have a little background. Aurichalcite is a copper-zinc carbonate mineral that is incredible fragile and looks like blown up muppet. Where can you find some of this stuff for yourselves? Well, if you feel like getting really frustrated and are in Utah (or nearby), look for it here…

Those dots are probably a little off, but they are within 50 miles or so. Probably. Also that map is really small, so this is probably going to be inconvinent to the hard of seeing. If you can make out the numbers, they are…

1. Lucin District

2. Gold Hill District

3. Big Cottonwood District

4. Park City District

5. Ophir District

6. Tintic District

7. Lincoln District

8. Bradshaw District

9. Dixie Apex, uh, mine.

There are likely a billion other places. So when I said it was rare what I meant to say was that it is pretty common. In Utah anyway. I don’t know how Kansas is looking.

And so, there we are. We know what it is, how it forms, where we can find it, and how I feel about it. That’s more than Wikipedia will give you. They think they’re so great! Just because they don’t have to make up stuff doesn’t mean that they are better than me!


Cheetah said...

I don't know what is going on with the spacing issue. Pretend that the whole thing isn't all messed up and it was the best thing you've ever read.

Anonymous said...

Do you have any gilsonite and/or ozokerite rocks for sale?

Cheetah said...

Ozokerite and gilsonite eh? I've got some pieces of both those buggers around here somewhere. Let me see what I can find and I will email you.