FMF - Friends of Minerals Forum, discussion and message board

[rickhz]

Found this at a calcite mine. The sample doesn't appear to be calcite though. Any ideas as to what this may be??

[chris]

As you are a new user you can't be faulted for not being familiar with the "rules" which are probably more like guidelines. When submitting something like photos, it is standard practice to always provide as much information as possible, thereby greatly improving the prospects of getting meaningful responses. You are welcome to post identification requests about mineral specimens on FMF, but if you want us to help you there are a few tests you should do and information you should provide. It will help us a lot and you'll learn a lot as well:

1 - Read the Asking: "What is this? / Where is it from?" topic. It contains information about basic tests. These tests are very important  in identifying a mineral. Without them, our guesses might be meaningless as different minerals look the same  in photos. The motto is: the more accurate the information, the better the answer. And please do not neglect to state the locality where the specimen was found, this is a great help in suggesting an identification.
 
2 - Then, read A general guide for using the Forum with some rules and tips It contains posting tips and a few basic rules about FMF we invite you to follow. Regular members do this. In your doing it too, you'll quickly be considered as a member of our friendly community.

Cheers
 
FMF Administrators' Team

[rickhz]

Read the check list. Didn't help. I don't have hydrochloric acid and I'm not going to purchase any for one sample. Just thought this piece was interesting considering it was just laying on the ground and must have been out in the open for decades as that's how long it's been since the mine closed. The mine was operated to retrieve calcite for the Nordon Bomb Site in WWII. The calcite "lens" was used to correct for parallax.

The calcite there looks nothing like the sample. Almost seems that someone dropped it out there.

Is the form of the sample I found relatively common? As in a small rectangle with one side highly polished?

As far as the matrix in the area, it appears to be limestone, and granite. The area outside of Salton City, CA was once ocean.

What I can add is that the crystals within sparkle like little diamonds and the color is a little more neutral than the photo depicts. The photo has a yellowish cast to it.

[lluis]

Hi, Rickhz

I could suggest some vinegar from that used to dress a salad.
If a sample from what you have fizz, evolves gass and dissolves, could very well be calcite.
If no reaction, by sure, no calcite.

If calcite, as far as I understand, could maybe be an aged rhomboedron, or a cut piece.
But could be for aspect a aged chunk of glass....

Without more data, a chunk of anything, is a chunk of anything.
A crystal in his matrix, we can identify. Although I always have an analysis for rare specimens .... :-)

Sorry.

With best wishes
Lluís

[rickhz]

I tried white vinegar. No reaction. It's definitely not glass.

Here's the backside:

[GneissWare]

[supertxango]

Also know streak color could help...

[Tom Tucker]

It looks like a man-made artifact to me.

[Pierre Joubert]

It looks like a biscuit! Whatever it is, it is fascinating and hopefully a very unusual mineral specimen.

[rickhz]

Just thinking about it. It almost seems like a cut out section of a geode... I found a local mineral club. I think I'm going to attend a meeting to learn what I can about it.

[Pierre Joubert]

[Jordi Fabre]

[rweaver]

To add to your above comments. The location of this is actual the Hilton Deposit located just outside of Borrego Springs. I spent a lot of time around this mine when I lived in San Diego and never came across anything like your pictures. A great reference if you can find one is the Mines and Mineral Resources of San Diego Co., County Report 3. This location is now part of the CA park system and I am sure in gets lots of visitors, know telling what one of them might have left behind.