To a geologist, granite is a particular kind of igneous rock.

In the commercial world, they like to keep things simple - there are a lot of types of stone but typically they group together all the stones that can take a polish and are about as hard as granite or harder and call them granite. Some of these are igneous and some are metamorphic.

Commercially, they sometimes use the term quartzite now, but they may be a bit loose with it like they are with granite apply it to things that aren't quartzite.

Quartzite is one of the stones that is often commercially called granite. It is natural stone - i.e the slabs that go on the counter were dug out of the earth in one piece. It started out as sandstone and was metamorphosed enough that it is smooth rather than having grains. It is composed almost entirely of quartz. Quartz is white/clear.

Quartzite may have other colors from the impurities in the stone. Some have very striking colors and patterns. A number of kitchens with those were on Garden Web when we were doing ours - Azul Macaubas (white and aqua blue), Wild West Green (mainly greens with some other colors including some pinks), Van Gogh (which does look like some of his paintings) and our Azul do Mar. At the moment there is a lot of interest here in the ones that are mostly white and as close as you can get to the look of marble in a hard stone.
Quartzite is very hard - it is harder than granite. We love ours - it's bullet proof.

I think you have your answer above. I have a white/gray quartzite counter, calledQuartzite Bianca or Luce di Luna. It is very hard and when sealed properly is (nearly) impervious to staining. It doesn't etch like marble, but has a rather similar look to marble.

Silestone, Caesarstone, Hanstone etc. are all man made "quartz" counters, not solid quartzite stone.

factory made (man made) materials need a name, and "quartz" is the term they gave it.

unfortunately.

but, since there was no other freely available term lying around unused and willing to be put to use, it had to do.

Thanks to all of you for the information. At least now I know that I can rule out "Quartzite" not the right color for me. Thanks,

I know that I can rule out "Quartzite" not the right color for me.

?

Quartzite is not a color.

Advanced, I am also confused by your comment. Quartzite color depends on the impurities and there is quite a range of colors - from white and grey marble like looks to blues and greens, browns, or yellows.

We didn't go out looking for quartzite. We just looked through the "granite" area of the stone yards for a stone that worked for us. Then checked with our fabricator and by testing the sample for etching to make sure it was one that was practical for our kitchen. It turned out to be quartzite.