FMF - Friends of Minerals Forum, discussion and message board

[Evan Phillips]

Hello guys. I am new and I apologize for incorrect format. But i found these in a creek in Northern California. Im wondering if they are jade. Ill get some daylight pics tomorrow

[James]

Please do some tests on it - hardness is the simplest. Number 8 on this page

http://www.mineral-forum.com/message-board/viewtopic.php?p=19487#19487

Jadeite is a pyroxene mineral with composition NaAlSi2O6. It has a Mohs hardness of about 6.5 to 7.0 depending on the composition so test it on quartz (7) or glass (6-7).

My guess is that you have found quartz or gypsum (much softer)

[Peter Megaw]

Nephrite is also legitimately called jade. It is a mixture of amphiboles and tends to be slightly softer than jadeite. Nephrite is hydrous and its green tends to be whiter. If your material passes the tests as jade...I think the color says it's nephrite


Most California jade is nephrite...there are some famous beach occurrences from south of Carmel to Oregon. There are also publications on jade by the California Geological Survey...you might find your occurrence is known

[lluis]

Dear Peter, James, Evan, List

I bow in front Peter's knowledge.
But still, I think same as James, just that I think that it is a stained quartz.
When young, at the beginning of times, I worked by a gross dealer in jewelry.
Nephrite could have this colour, but generally is more apple green (the top...) with black points, or dark green (the Russian jade).
No one looks as that...

Still, I side James.

With best wishes

Lluís

[Peter Megaw]

I agree on quartz too but he should follow James's suggested protocol to narrow things down...

[Paul Biehler]

It could be idocrase from near Happy Camp in Siskiyou County. A location where you found it would be helpful. It does not look like California nephrite to me.

Paul

[Evan Phillips]

Thank you gentlemen. I will be conducting some hardness tests.

[Evan Phillips]

So far I can tell you that it will scratch a beer bottle (glass ). And that the best I can tell without cutting my finger off, the glass will not scratch it.

[Evan Phillips]

Another side of same rock

[Evan Phillips]

And another

[alfredo]

Mindat gets so many questions about identifying jade that I once wrote a brief how-to guide:
https://www.mindat.org/article.php/883/Jade
In your case I think you have found a rock type called metachert, but do some tests to eliminate other possibilities.

[Gagat Minerals]

first stone on the left - could you please test white parts with HCl?

[Jim Robison]

Most jadeite and jade has an internal, though not always visible interlocking mineral texture that makes it tough, and it doesn't fracture easily. The pieces pictured all have a lot of visible fractures which all by themselves pretty much rule out jade like rocks. The dense nature of jade and jadeite makes it an ideal stone for carving with great detail, which is why you see so much of it in carved figures and bowls.

[Evan Phillips]

Just want to say thank you guys for all the help. I am truly impressed by the level of knowledge and experience that you all have, and I appreciate you taking the time to help me. I realize I should have read more and done some more tests but I was so excited I had a newbie moment I suppose. I always loved rocks and minerals because I feel like they have such a story Anywhere else that might sound crazy but maybe you guys understand. I get almost as much excitement from a cool rock as a fine diamond or etc.
When I get home I'll post some pics of a fossil I found as a kid. Three pieces of a leg that all fit together. The guy who owned the land I found it on said that it was most likely from an animal that was one of the first pig families. But still cool

[James]

Thank you Alfredo

[Jordi Fabre]

[Evan Phillips]

I won't post them then but technically the fossil is a mineral isn't it?

[Dale Hallmark]

Not always. Where I live there are plenty of fossils that are mostly impure limestone...which is a rock and not a mineral.

Dale

[Roger Warin]

Fossil is a rock.

[Kevin Schofield]

Well, so long as we are all having fun counting the number of angels dancing on the head of this particular pin, I may as well throw in my 50 cents-worth and say that I think that Evan is a little more correct than Roger here, but both are over-simplifying.

A fossil is, strictly speaking, the preserved facsimile of a formerly biologically-mediated entity. It may be mono-mineralic and largely unaltered (sharks' teeth: calcium phosphate), mono-mineralic chemically-identical but but altered in crystal structure (many fossil shells are now calcite, but were deposited as aragonite, which is an unstable polymorph once burial commences), mono-mineralic but wholly replaced by a different mineral (pyrite or silica replacement of carbonate), be a direct replacement of biological structure by a mineral ("petrification" of wood as the cellular structure is replaced by silica), or, indeed, much of the the biological structure and chemistry may be preserved within a "pseudo-mineral" as spiders are in amber or fossil leaves are in coal (carbon remains, oxygen, nitrogen, hydrogen all gone).

On the "rock" front, occasionally when the biological material is dissolved away during shallow burial, the resultant cavity may be filled by percolating sediment (mud or sand), so the eventual "fossil" may indeed be a piece of rock...fossil tree trunks in coal measure are often preserved like this.

And then, of course, there are the rocks that are made up entirely of fossils, sometimes still only made up of one mineral: chalks, reefal limestones (calcium carbonate) and diatomites (silica).

Probably more than you wanted to know Evan :-)