Well, actually, the statement that "Granite is less permeable than marble." Is an inaccurate generalization, based on misinformation that gets repeated so often, folks just take it as fact. Unfortunately, lots of so called "experts" are complicit in spreading this misinformation. Classic blind leading the blind.

In addition, honed finishes look nice, and I do also recommend them sometimes, but honing opens up porosity by vastly increasing the texture - surface area - of stone, increasing the maintenance a bit, in terms of sealing and cleaning. Honed material will always appear unevenly finished, partly due to the actual finish structure, but also due to material such as skin oils, and other inconsequential residues, getting into the micro scratches that make up the honed texture. It's a nice look; folks need to understand the reality of it before they live with it.

Most stone sold as granite is not. For convenience in serving the market, we lump non-calcareous veneer stone into a broad group solely for Marketing purposes. The small selection of true granites within that mercantile classification are distinct, and are - in fact - more porous than most marbles. They also have a distinctly chunky/granular appearance. Their resistance to heat and acids is very high. Granite is used as production tanks for hot acid in metal plating. It's the substrate of choice to pour molten metal onto, to form high accuracy test plates. Most of what you see in kitchens is NOT this tough igneous stone.

Marble is calcareous metamorphic stone. It is primarily calcium, a metal. The basic porosity values tend to be low, and surface porosity is affected by the polishing process, which for many of them, will close down the surface pores considerably. As the calcium reacts - essentially melts - it fills in pores. The porosity will be determined largely by the mix of minerals that do not react the way the calcium carbonate does. Much more can be said about this, but the practical information is that ANY calcium based material is subject to chemical and mechanical damage, regardless of porosity or impregnating sealer. The staining comes from oils (lower surface tension than water), and from etching that opens up porosity, and surface area.

Marble will etch from exposure to milk (lactic acid) fruit juice, meat, coffee, salad dressing, glass cleaner, stainless steel polish, strong bleach, even sometimes water. It looks great when new, and also, after it's really old and beat up. Unfortunately, most of us aren't too fond of the in between part.

Engineered quartz can be a nice alternative to marble. The LG product is good, so is Caesarstone. The stuff is sold as some high percentage of quartz to resin, which is true in terms of weight, not volume, so the claims are a bit misleading. Rock (quartz) weighs a lot more than plastic. You need to know that all those white and light resins in engineered quartz will yellow a bit with age, regardless of sun exposure, with more pronounced effect with more sun.

There are natural quartzite stones available that look like white or light gray marble. Depending on what's available to you when you need it, you could find something only a stone expert would recognize was not marble. If you go that route, get a sealer recommendation from the slab warehouse (dealer).

No matter what material you consider for your kitchen, I recommend you test it for resistance to food acids. Get a sample of the actual slab you have on hold for your kitchen, have them cut or break off a corner for you to take home. Cut a lemon in half, press the cut side to the stone sample, leave it there for a while - an hour, or overnight even, if the material is stable, it won't matter how long you leave the lemon on it. Remove the lemon, rinse, let dry, and inspect. If you see a light or dull impression where the lemon was, the stone is etched - find another stone for your kitchen. If the finish didn't change, but the stone is darker, that's moisture or rind oil, and not an issue when the stone is sealed.