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Fakes & FraudsBrazil twin

18th Oct 2012 08:10 UTCHans Kloster

In many books, almost every with explanation of quarz twins, they have the brazil twin, but I have never seen a brazil twin. Does the brazil twin exist?

18th Oct 2012 11:08 UTCRoger Curry

Smoky Quartz, Microcline

Mount Malosa, Zomba, Southern Region, Malawi

Hi Hans,

You have to look closely at the crystals to see if you have one, they're a combination of right & left hand crystals - more info & pics on Amir's brilliant quartz site here

Regards,

Rog

18th Oct 2012 20:05 UTCTim Jokela Jr

Holy hell, that is a neat quartz crystal!

18th Oct 2012 20:27 UTCAmir C. Akhavan Expert

Aleksander knows a lot more about twins than me, but I am not sure that this is a Brazil law twin.

Remember that positive and negative trapezohedra can both show up on a single crystal.

A bipyramidal face surrounded by two positive or two negative trapezohedra could be interpreted as a representation of a "non-existing" twin, Liebisch/Combined "Law", but this would not indicate a Brazil law twin. So it is not unlikely that what you see is a combo of different steep positive and negative rhombohedral and positive and negative trapezohedral faces.

One can cut the crystal and check, of course :-D

18th Oct 2012 23:17 UTCRudy Bolona Expert

I prefer this Brazil twin;

18th Oct 2012 23:21 UTCAmir C. Akhavan Expert

But these are obviously Dauphine twins! :-D

19th Oct 2012 09:49 UTCRoger Curry

You're right Amir, the vicinal faces & growth hillocks are indicative...