I wanted to get back to you with more details about my acid washed marble. I asked my fabricator Austin from Dominion Granite and Marble in Ashburn Va to explain and this is the great explanation he gave:

For your knowledge let me explain the difference between a honed and acid washed finish.

Honing is a step along the way to a fully polished stone. Most countertop grade materials are ground and polished to a finish of 10,000 grit also known as the diamond 10 finish. This polishing process starts with a 30 grit diamond and makes about 7 stops along the way to diamond 10. Most honed materials are polished to either a 400 grit or 800 grit finish. Certain types of stone will not accept a full polish based on the type of material. Stones like travertine, limestone and soapstone will only go to about 600 grit and will not change by going any further.

Using honed marble has become a very popular option as a deterrent to acid etching. When a calcium based material like marble is introduced into a kitchen enviroment bad things can happen. Acidic household liquids from coffee to lime juice can etch or "burn" the material. Think back to mixing baking soda and vinegar in school and this will remind you of an acid/base reaction. We typically do not encourage honing as a way to blend etching due to the uniformity of a honed material.

When you look at a honed countertop that has had an acid etch you will be able to spot the damage almost as quickly as you would if the countertop has been polished. For this and other reasons we encourage acid washing.

Acid washing is a new take on a very old Italian tradition. In Carrara Italy is has been a custom for many generations to smash tomatoes on your white marble countertops before their first use. Outside of being fun to do this would accomplish two things. The material would be uniformly stained but it would also etch the entire surface due to the citric acid. Now in the 21st century we will manufacture a white marble countertop with a full polish then treat it with acid under controlled conditions. Through material testing we can determine the approximate amount of acid needed to yield a uniform acid washed finish. Muriatic acid is mixed with a certain amount of water for dilution, pressurized, sprayed onto the marble for a pre-determined amount of time then washed off. Not only is this process more cost effective than honing but it yields a finish that has a slight texture which is more desirable for long term use. Once washed we will impregnate the tops with an oliphobic impregnator to protect against staining and you are good to go.

Etching will still occur in the future but you will not be able to tell where the etching took place as the entire surface has a slight texture to it. This would be akin to a textured faux finish instead of a high gloss or flat paint job. We have been acid washing countertops for over 10 years and have never had a complaint. Most people have never heard of the process so we try and educate them on this option.