There is sheetrock in them thar hills

[desdawg]

We had a warm weekend in the mountains so I sallied forth to take advantage of it. I excavated a pad so I could get a land sea container delivered and have some secure storage. As I was digging the soil started turning white.

I had run right into a gypsum deposit. So if you have never seen raw gypsum here is what a couple of nodules look like:


This is exactly the same material you find between the paper of your walboard. Apparently all that is necessary is to crush it and roll it out into sheets. The larger samples in the top picture have a little more of a yellow tint which may indicate the presence of some sulpher content. The material is soft and crumbly as it comes from the ground just like the material you buy only without the paper.

[glenn-k]

Cool, desdawg.  You gonna figure out a way to make use of it?

[desdawg]

I think if I had dug just a little deeper I would have been pulling out 4X8 sheets. But I started feeling trogloditic and I had to quit.  :-/

[glenn-k]

If you had dug a bit deeper and put a roof over it, all you would have to do is wet the walls with a sponge - rub a little and you would be done.

[desdawg]

Wow, great minds! I was thinking I would just have to sand & paint. Actually I have been reading about "natural plasters" and many of the old lath & plaster houses were done with a gypsum plaster. Plaster of paris is made of gypsum. So you can use it just the way I found it for a few purposes and it will do just fine in an interior application. Now that I have my own gypsum mine I will have to do some more reading and decide how I want to use it.  

[Amanda_931]

Run into white stuff here, too.

There's a white clay (I have pin-head sized pieces up the hill), and some whitish veins in the red clay.  And something that seems to be called chalk.

wonder if any of them are gypsum.

So gypsum requires less processing than lime (which needs heating in a kiln)?

[desdawg]

Hi Amanda. According to the book I am currently reading, "The Natural PLaster Book, earth, lime and gypsum plasters for natural homes" says this about producing gypsum plaster: Gypsum plaster is made by heating gypsum at low temperatures to drive off water. This produces plaster of paris. If heated at a higher temperature the resulting product is anhydrous calcium sulfate. This substance is most commonly used to manufacture drywall and drywall compound. It is also used as an interior plaster. It goes on to say that natural gypsum is by far the best plaster on the market. However in it's pure form it may be difficult to locate. I guess a lot of manufacturers add different chemicals for various reasons, i.e to speed drying time, increase fire rating, etc.
Anyway, it would seem that your chalk could be gypsum. The book says it is widely distributed throughout the earth's surface. Pick up a few samples and play with them a little and see what you think.

[Amanda_931]

I have that book--somewhere.

So I guess I'll go down to Chalk Creek and find some "chalk"

[desdawg]

The book doesn't state what "low temperatures" and "higher temperatures" mean exactly. Somehow Amanda I am not surprised that you have that book.