Biotite?

[www.mindat.org]

Mica Group. Biotite-Phlogopite Series.
Synonym of:Annite, Eastonite, Phlogopite, Siderophyllite

The micas on the biotite end of the series, including Annite, Fluorannite, Tetra-ferri-annite, Siderophyllite.

I find this confusing. If Biotite is a discredited species how can it be an end member? and how can biotite be a synonym of phlogopite?

Biotite used to be black mica coloured by lots of Fe. Perhaps "biotite end of the series" should be replaced by "the iron rich end of the series", but others will know better.

There's a problem with Synonyms. Suppose something B is closely related to an IMA defined species A. If All of B is exactly all of A then we have a synonym like Idocrase and vesuvianite. Then if all of B is some of A then B is probably a variety. . However in the case of Temiskamite and Maucherite, all the Temiskamite was misidentified Maucherite. So it got called a synonym rather than a locality variety. Finally B can be some of A or some of something else. This is the case with mixtures and things like biotite which aren't mixtures, However we seem to be at a loss for a good name for these "synonyms"

Fixed.

There are still a few problems showing up here. Biotite was listed as a synonymn, and listed with synonynms Annite, Eastonite, Phlogopite, and Siderophyllite. These are endmembers to the series, not synonymns. I have changed biotite to a series, but it will only accept two endmembers, so I used Annite and Phlogopite, though the others should be added, plus Fluorannite, Tetra-ferri-annite, Fluorophlogopite and Fluorotetraferriphlogopite. Probably it should be a subgroup rather than a series, due to the complex substitutions. I cannot get rid of the "synonymns". I also added biotite to the list of micas, and changed illite to a series. I know the micas are under review, so if anyone has better ideas on their status, please let us know.

Regards,
Ralph

A series is A to B on mindat. Anything else must be a group.

Jolyon

I am starting to hate the word "synonym"... we seem to have hundreds of uses of the word scattered through Mindat which are not technically correct. As Rob pointed out, "synonym" implies equivalence of meaning, as in idocrase-vesuvianite. When A is a subset of B, they cannot be "synonyms".

I agree Alfredo. I also like Jolyons version of a series better than the IMA one.

Regards,
Ralph

On mindat. A can only be a synonym of B if B is also a synonym of A

So (examples) Selenite is NOT a synonym of Gypsum Herkimer Diamond is NOT a synonym of Quartz.

If there are examples on mindat where we have synonyms listed when they should be varieties, or something else, then please change them!

Jolyon

Hmmm... Then Temiskamite is not a synonym for Maucherite. In fact according to Dana's Textbook it is a mixture!!! I'll fix it.

I tried several times to change Biotite from a series to a subgroup but it keeps reverting to a synonymn.

Regards,
Ralph

Ralph, there appears to be a larger force at worek. Perhaps the Biotite doesn't want to change...

John

Psychiatrists won't change light bulbs unless the bulbs want to change!!!

Bad luck biotite, I'm going to change you for your own good!
(If I could only work out how?)
I cannot even delete the "synonymns"

Regards,
Ralph