true quartzite is fine in the kitchen. stronger than granite. depending upon the calcite composition of your particular slab, will determine whether or not it's prone to etching or staining.

if you can obtain a little scrap piece, try running the edge across a glass tile. does it scratch the glass? it's quartzite, not marble. do the lemon test. did it etch? if not, great. you're fine.

you can also get this quartzite leathered or honed.

Run a beer bottle down the edge of that slab and see if the glass gets scratched, please. A woman just paid me $400.00 to remove the etches from her "quartzite". Don't believe a thing the stone salesman says or prints. The beer bottle (and lemon) tells all.

Thank you for your replies. The stone is already at our installer so I may be too late!

Would still make sense to test it to see what you have. That way you would know for sure how you need to treat it once it's in your home. As suggested, get a cheap glass backsplash tile at any tile store. Find the sharpest corner of the tile, then try to scratch the slab with it (easier to see on the polished top than the sides...). Push hard - try to do some damage. You'll know immediately. If the glass digs into the stone and makes a scratch (like it did on the "fantasy white" that the lady was trying to sell to my wife as quartzite), it's probably a dolomitic marble, is soft, and will act like marble. If the glass slides easily across the surface of the stone without leaving marks (or actually starts removing glass from the tile), it's quartzite or granite.....