FMF - Friends of Minerals Forum, discussion and message board

Thanks again.

(I got into this when I was trying to understand why two (adjacent) (prism) faces of an amazonite xl showed "reentrant" angles, which I've taken to imply (suggest?) twinning.

...although ...

Thanks again!

You're obviously right about the xl of this thread.
...something that I should have noticed immediately myself

I guess I must've taken the Page that I saw this on as truth - w/o a ...

Very cool! thanks

I never learned - or heard of (?) - that twinning always increases symmetry.
(& never managed to get classes, point groups , etc. into my head)
(& I'm a mathematician!) ...

I was just looking around researching twins a little, and came across this..
https://www.tulane.edu/~sanelson/eens211/twinning.htm
(link normalized by FMF)

..which looks an awful lot like the aqu ...

Author	Message
Topic: Is this a twin?
PMH Replies: 28 Views: 103204	Forum: Minerals and Mineralogy Posted: Jan 20, 2012 14:49 Subject: Re: Is this a twin?
PMH Replies: 28 Views: 103204	Thanks again.
Topic: Is this a twin?
PMH Replies: 28 Views: 103204	Forum: Minerals and Mineralogy Posted: Jan 20, 2012 14:08 Subject: Re: Is this a twin?
PMH Replies: 28 Views: 103204	(I got into this when I was trying to understand why two (adjacent) (prism) faces of an amazonite xl showed "reentrant" angles, which I've taken to imply (suggest?) twinning. ...although ...
Topic: Is this a twin?
PMH Replies: 28 Views: 103204	Forum: Minerals and Mineralogy Posted: Jan 20, 2012 14:02 Subject: Re: Is this a twin?
PMH Replies: 28 Views: 103204	Thanks again! You're obviously right about the xl of this thread. ...something that I should have noticed immediately myself I guess I must've taken the Page that I saw this on as truth - w/o a ...
Topic: Is this a twin?
PMH Replies: 28 Views: 103204	Forum: Minerals and Mineralogy Posted: Jan 20, 2012 10:02 Subject: Re: Is this a twin?
PMH Replies: 28 Views: 103204	Very cool! thanks I never learned - or heard of (?) - that twinning always increases symmetry. (& never managed to get classes, point groups , etc. into my head) (& I'm a mathematician!) ...
Topic: Is this a twin?
PMH Replies: 28 Views: 103204	Forum: Minerals and Mineralogy Posted: Jan 19, 2012 12:47 Subject: Re: Is this a twin?
PMH Replies: 28 Views: 103204	I was just looking around researching twins a little, and came across this.. https://www.tulane.edu/~sanelson/eens211/twinning.htm (link normalized by FMF) ..which looks an awful lot like the aqu ...