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Identity HelpMineral help? Please =)

1st Mar 2012 16:31 UTCMatt Wall

Hi there everyone,

found this at Judkin's Quary, Nuneaton, UK last weekend. I am just wondering what the minerals are. The mixture of minerals (rock) has a pink/cream crust on the top and is very soft, like talc, it can be scratched with a fingernail. The rock also has a clear fluorite looking sample on the edge of it, hopefully seen in the last photo.

Could anyone please name the minerals?

Thanks, it would help me.

Matt =)

1st Mar 2012 16:37 UTCJolyon Ralph Founder

No photos here

1st Mar 2012 16:57 UTCMatt Wall

Oh yeah, stupid me!

Sorry, here they are! =)

Thanks, Matt

1st Mar 2012 22:01 UTCJosé Zendrera 🌟 Manager

It looks a granitoid rock composed by quartz (gray grains), feldspar (orange grains) and a unidentified third mineral (blue/green). The soft material should come from feldspar alteration.

1st Mar 2012 22:34 UTCsteven garza

Dear Matt;

I agree with Jose, that you have a a granitoid rock (probably a piece of pegmetite - a super-sized grained granite) & his 1st 2 IDs; but, I also have a possible ID on the blue-green material. Although you did VERY well, photoing that specimen, there are things that your pics needed to show, that, only on CLOSE inspection (@ 200X zoom; the pics' zoom feature was WAY too much, to use properly - must be close to 400X or more), did I see possible poor cleavage on those sections; I only saw it going in one direction, on all the pieces, so, I'm guessing it only has one cleavage plane. My guess is fluorapatite, probably a mangoan variety. Try using a UV (long or short wave) to see if it has a yellowish or orangish fluorescence; it may also phosphoresce, shortly after the UV light is out (this happens under short wave exposure, only).

Nice find; KOR, dude!

Your friend, Steve

1st Mar 2012 22:59 UTCRonald John Gyllenhammer Expert

Hi Matt,

> "a pink/cream crust on the top and is very soft, like talc, it can be scratched with a fingernail."

Good advise from Steve and Jose but although the images may look a little like pegmatite, I don't think this locality hosts one. Further, there are not many pegmatite minerals that can be scratched with a fingernail. You should look at the Judkins Quarry photo page http://www.mindat.org/gallery.php?loc=1631 and compare with some of the images posted there. You might conduct some of your own tests to check the hardness of each distinct mineral. You can also check to see if any of the distinct minerals reacts with vinegar. Record your results and let us know if you can. Good luck Matt.

Ron

2nd Mar 2012 00:20 UTCJosé Zendrera 🌟 Manager

Ron is right, I was wrong. Things are that they are, not that they look! There is not granitoids in Judkins Quarry, I was too fast answering without knowing the zone.

After see the link suggested by Ron let me make a second attempt, today I am bold:

orange = barite

gray = calcite

green = sphalerite?

2nd Mar 2012 16:31 UTCMatt Wall

Thanks guys for all your help,

Judkin's Quarry is a granite quarry, it could be barite leached by some other mineral.

Also. the mineral isn't fluorescent or phosphorescent.

Thanks, Matt =)

2nd Mar 2012 16:35 UTCsteven garza

Dear Matt;

I, too, must agree; I think Jose has nailed it.

Your friend, Steve

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