Dear Pat:
For starters,
a stain – a real stain – is always darker than the stained material. If it is lighter, it's either a mark of corrosion created by an acid (etching), or a caustic mark created by a base (bleaching). There are no known exceptions to this rule. In the case of natural stone, bleaching can't occur, and therefore they are etch-marks all the time: plain and simple surface damages, like shallow chemical scratches. The acidity of your drink did the deed.
That duly said, you now understand that you have a surface damage to deal with, not a stain to be removed.
So, how do you go about that?
With a marble repair kit.
The centerpiece of such kit – which is probably all you need – is a polishing powder for marble that was formulated to be handled by non-professional consumer. Keep in mind that black marble is only second to green marble as far as difficulty of face polishing is concerned, but it will work!
May I ask you now to please read and e-sign our Statement of Purpose at:
http://www.marblecleaning.org/purpose.htm?
Ciao and good luck,
Mauri
Article ID: 937
Created On: Sat, Dec 22, 2007 at 7:15 PM
Last Updated On: Sat, Dec 22, 2007 at 12:00 AM
Authored by: Maurizio Bertoli [mail@mbstone.com]
Online URL: https://marblecleaning.org/knowledgebase/article.php?id=937