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Identity HelpBavenite or bikitaite - Foote Lithium Mine, NC

3rd Jan 2018 18:36 UTCDon Saathoff Expert

Hello All,

I've been through Mindat's Foote mine pics a dozen times (maybe a slight exaggeration) and have settled on either bavenite or bikitaite as the ID of this little spray - it is just over a mm in diameter. Considering the habit (spray) I decided it is most likely bavenite but before I add to the database I'd like more opinions....

Don S

3rd Jan 2018 20:58 UTCReiner Mielke Expert

The modified terminations and striations along the length of the crystals suggests to me bikitaite not bavenite.

3rd Jan 2018 21:35 UTCDon Saathoff Expert

Thanks, Reiner,

I shied away from bikitaite simply because of the orderliness of the spray. But, the striations were a reason for it's consideration. The terminations also seemed more regular (basal?). Any more suggestions, anybody?

Don S

4th Jan 2018 01:19 UTCDonald B Peck Expert

Hi Don;

Based on the terminations, I agree with Reiner. Do you have a petrographic scope? If you do, and there is a tiny xl somewhere else on the specimen that could be sacrificed, Bavinite will go to extinction with the long edge parallel to the cross-hairs. Biktaite, if the xl can lie so beta can be seen, will go to extinction about 25^o off parallel. Alpha and gamma are too close to 90^o to call. I have a feeling that the natural position will expose alpha, not beta. but . . . .

Don

4th Jan 2018 01:59 UTCDon Saathoff Expert

Hello Don ,

Thank you for the information but I no longer have a petrographic 'scope. I will, however, add your bikitaite vote to the total!

Don S

edit: OK, after three days of fasting, a couple shots (or three) of good whiskey, my vision told me that Reiner & Don are right - I'm uploading the pic as bikitaite.....

29th Jan 2018 09:23 UTCJason B. Smith Expert

Hi Don. Just got your message, sorry I don’t check them as often as I should. Actually what you have there is bertrandite. Bavenite never occurs in blades this thick at Foote and bikitaite, especially this small, will have obtuse chisel terminations. Also it never tends to grow in groups originating from a single point; typically they are found as single crystals even if there are quite a number of them. Attached is a quick phone photo of what bikitaite looks like when there are numerous, smaller xx.

29th Jan 2018 18:14 UTCDon Saathoff Expert

Thanks Jason!! I'll go in and edit my image with you as the reference...

I've got one more unk which I haven't been able to photograph yet (it's DEEP in a pocket), looks to me like a pale blue fluorapatite - I can see two prism face edges at the seemingly correct angles and a perfectly flat termination (if I'm looking at the xl correctly; it's embedded in matrix!).

Don S

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