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Identity HelpAnother crazy Rawley Mine piece

22nd Mar 2009 02:20 UTCCorie Mattar

Hello. This was collected from the Rawley mine dumps. It has these weird little half-orange, half-white pieces in and on it.

At first, I thought gravity had something to do with why the pieces are exactly half-colored, however they are not all half-colored, some are spotted, and they are not in alignment. That is to say, on some the line is horizontal, on others, vertical. Does that make sense?

The specimen consists of galena, and what I originally assumed was quartz. The orange-white pieces scratch quartz however, so its hardness is greater than 7.

No flourescence under high or low, other than the thin coating of calcite on some parts of the piece.

There is one large solid white xl that looks slightly like willemite, however, hardness and lack of florescence seem to preclude that as an ID.

Any ideas?

First pic is the whole specimen, approx 10cm x 10cm by 7-8cm.

Second pic is the white xl, approx 13mm long.

Third pic is a few of the orange-white pieces. Approx 7mm on the largest one.

Thanks for looking!

Corie

22nd Mar 2009 08:32 UTCSebastian Möller Expert

Hello,

Looks like quartz at all. The orange colour is mostly due to iron bearing inclusions (for example hematite) and/or a thin hematite coating.

Regards,

Sebastian Möller

22nd Mar 2009 08:51 UTCRob Woodside 🌟 Manager

ditto

25th Mar 2009 20:22 UTCCorie Mattar

Sorry for the delay in responding (lifus interruptus!).

Thanks for the info! I think what threw me was that it scratched a solid quartz XL, yet all the xl did was leave a streak on the quartz.

I know that quartz can be harder or softer that 7 MOHS, I just assumed that a large (6cm) xl would be harder than microcrystalline.

Why would the inclusions settle in exactly half of the quartz, and in only some of the pieces? And those half-pieces are in different directions?

Or is this just one of those mineral mysteries? :S

Thanks again, I really appreciate the info! :)-D

Corie

25th Mar 2009 22:34 UTCRob Woodside 🌟 Manager

A geopetal flow will deposit overgrowths on the same side of everything, but I think what you have here is the accidental placement of small pyrites which rotted to the red and diffused through accidental fractures to give the odd picture posted above. Maybe an accident is a poorly understood mystery.

26th Mar 2009 04:55 UTCCorie Mattar

Pyrite, huh? I'll go with the accidental fractures theory.

Could it have been vanadinite instead of pyrite, though? I'll admit I do not have any pyrite from the same location, but I did recover a specimen with microcrystalline vanadinite, although it was redder.

Thanks, Rob!

Corie

26th Mar 2009 05:13 UTCRob Woodside 🌟 Manager

I only suggested pyrite as a common source of iron staining and it could be long gone. If it is not iron staining I don't know what it could be.

26th Mar 2009 05:21 UTCCorie Mattar

Thanks again. Sometimes I overthink a thing. :)-D

Corie

26th Mar 2009 07:28 UTCBarry Murphy

Hi Corrie,

I was lucky enough to collect there over a 5 yr period. I'm neither a geologist nor mineralogist, just a collector. Wonderful place for micros!

In all my trips there I never found a piece that contained Pyrite (sorry Rob), BUT there is a ton of Hematite. I'd guess that most of the red country rock around Rowley is stained by it. There is also a LOT of chalcedony, not only in the dumps but scattered aound the country side. That may be what you have there. Any orange or yellow staining is likely due to the massive amount of Mimetite there.

Hope that helps a bit.

Cheers,

Barry M.

28th Mar 2009 01:23 UTCCorie Mattar

Thanks, Barry!

I get there every couple years or so. My collecting pal and I got very lucky last time, and there were miners who traded with us and let us collect from the tailings.

We also got some great agates from an area just a mile or two down the road towards the dam. Apparently there is a hill the kids like to 'party' on, and we picked up some beautiful banded agates right out of the tire tracks!

Thanks again for the info,

Corie

28th Mar 2009 08:34 UTCRob Woodside 🌟 Manager

Thanks Barry. Hematite it is. I've never been there.

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