Is this Biotite?

I'm quite sure this is of the Mica Group but can anyone tell from these pics ( SEE ATTACHMENTS BELOW) if it is biotite. It is much blacker and shinier and sparkly than this phlogopite I found at the same location.
Thank you for any help
16cm x 9cm x 5cm
John




Edited 1 time(s). Last edit at 05/11/2012 07:00PM by John Montgomery.

Biotite is not a species name. let alone a distinct species from Phlogopite. Rather it is a "catch all" term used for the various darker micas of unknown composition (not analyzed).

MRH

Hi Mark
I notice you have a specimen of "biotite" on you photo page. I'm just wondering if I should do the same ...ie. as opposed to "Mica group" or "phlogopite"
thanks
John



Edited 1 time(s). Last edit at 05/11/2012 08:35PM by John Montgomery.

Looking at all the photos on Mindat around the area I collected this specimen, it seems to me that this is biotite. Do others concur?
Thanks John



Edited 1 time(s). Last edit at 05/12/2012 12:47PM by John Montgomery.

Without analysis or published confirmation of which specific species is generally observed at the site (for some complex geological areas, this will not be sufficient as several similar looking dark micas will occur in various zones), yes, I think Biotite would be the preferred I.D. to use. The Glen Mills Biotite of mine is "biotite" for that very reason.

BTW, I do LOVE the dark micas, and I have quite a number of really nice pieces from Quebec and Ontario. Particularly nice "Biotite" to be found up there, to be sure!

MRH

Many thanks again, Mark
John