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PhotosRhodonite - Broken Hill, Yancowinna Co., New South Wales, Australia

16th Mar 2013 13:29 UTCTrevor Dart

Bustamite, Galena

Broken Hill, Broken Hill district, Yancowinna Co., New South Wales, Australia

Nice piece, very nice crystal, excellent photo.

My only question is:

Could this actually be bustamite and not rhodonite?

I have seen so many Broken Hill pieces like this labelled rhodonite but they are in my opinion not red enough to be called rhodonite. The bustamite from Broken Hill is more like this colour, tannish brown with a light pink tinge. There is a fine line between the two as their crystal structure is so similar it cannot be used as a confirmed test. Without getting the sample chemically analysed, does anyone have a rule of thumb to distinguish between bustamite and rhodonite from Broken Hill.

Trev

23rd Mar 2013 22:07 UTCKeith Compton 🌟 Manager

Hi Tev

I'm inclined to agree.

Any of those brownish "rhodonites: could easily be or more likely be Bustamite.

There seems to be very little research into these species from Broken Hill

Cheers

25th Apr 2013 23:59 UTCRalph S Bottrill 🌟 Manager

I would agree with bustamite. You can tell by XRD, though the structures are similar and the chemistry can be close too. Interestingly though with some of these bustamites you can get exsolution inter growths of the two, and hedenbergite also, which gives reddish and brownish colours, and really screws up the XRD patterns. I could send a complaint.

26th Apr 2013 06:16 UTCBen Grguric Expert

Incidentally some of the deep red 'rhodonite' from Broken Hill has been found to be pyroxmangite.

26th Apr 2013 08:37 UTCRalph S Bottrill 🌟 Manager

Yes Ben, probably a large proportion, at least in the Zinc lodes, where it's about 50%, but it would be good to look more systematically at the relative distributions through the different lodes.

I sent a complaint on the bustamite.