I recently tested a honed piece of Mont Blanc (not the grey background version that is also called Super White, but the crystalized version that I believe is also called by both Shadow Storm and Snow White; may be called Princess White or Iceberg as well?). Tested with lemon, ketsup, coffee and water left on overnight and it did etch and stain but barely noticeable if at all. Here is it with a piece of polished Carrara for comparison. At the bottom right of the Mont Blanc you can see a shade of stain from ketsup and coffee - actually seems more noticeable in pictures - but you can see the etching very obviously by comparison on the Carrara (you may need to click on picture to see entire photo).