Dustin,
Black granite doesnt etch from household stuff so more than likely the stone was coated with something like a sealer or it was doctored maybe. Always check before taking out the diamonds. Color enhancing and sealing black granite wont fix a polishing issue
That areas looks bad-definitely clean off the the entire surface of any leftover sealer residue or waxes using 5x or your favorite solvent. You need some good quality diamond pads like alpha's or shine pads(and an alpha black buff wouldnt hurt). Like fred says you gotta run your diamonds from wet to dry. Try starting at 800 with quality diamonds and go up from there blending out of that dull spot. You may need to start lower if you have to eliminate any profile that may be there.
Keep the area as tight as possible as you already have an epic adventure in the making. If this is the first time polishing black granite do yourself a big favor and get a practice piece to work out the sequence before you go back to the vanity(you will be glad you did).
If the stone hasnt been doctored just badly maintained and you can get your work area looking a bit better in clarity and luster(get rid of that ring) you may be able to make it pop with MB-20. I think it may be worth a try but you may want to reach out for someone who can help you with this job and explain the use of the diamonds which probably the most important part of the process.   

On Mon, Dec 13, 2010 at 10:16 AM, Dustin Fox <foxmarine@gmail.com> wrote:

I'll give that a try. Thanks

-Dustin

On Dec 13, 2010 9:38 AM, <srsdenver@gmail.com> wrote:

If you had an etch ring on black granite my experience tells me that there is something on top of the stone. If one does not get it off marking will continue. I would suggest a good 5X of the whote surface which should remove anything that is sitting on the stone. Then powder polish, sealn or Dr. Fred's suggestion

Sent on the Sprint® Now Network from my BlackBerry®


From: Dustin Fox <foxmarine@gmail.com>
Date: Mon, 13 Dec 2010 09:27:46 -0600
To: Restoration and Maintenance<sccpartners@stoneandtilepros.com>
ReplyTo: "Restoration and Maintenance" <sccpartners@stoneandtilepros.com>
Subject: [sccpartners] Black Granite repair



I am in need of some ideas from the group. I had a small repair job on a granite counter top from ...




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Stu Rosen
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www.mbstonecare.com
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