Polishing Uba Tuba

First let me say I enjoyed reading many of your comments. I have cut and installed my ow counter-tops (30 mm darn heavy to say the least!); however, when I was finishing the grinding and polishing of the undermount sink I noticed that I have the same feel to the stone at 3000 grit, but it just doesn't match the shine of the factory finish where it meets on the top. The results on the edges are very good, but on the top where I did some additional polishing in a small area that had a small blemish, it remains somewhat duller than the factory finish. I has polished out some other softer stone with mirror like quality, so I was wondering about any other techniques. I had read about resin coats that are added to courser stone like uba tuba and was wondering if I need to apply some type of coating or if going to a finer grit (4000 - 5000) wound bring out the final sparkle?