Self-Testing the Properties of Your Stone:

As you begin doing research for your countertop project, you’ll quickly find that there are a plethora of generalizations about the properties of natural stone (i.e. “the properties of granite” or “the properties of marble”). For the most part, those kinds of general qualities about stone are an excellent starting point for your research, but it is important to remember that every single rock is entirely unique – in beauty, and in natural properties.

There are three important qualities that you should find out about your stone before making a final decision: the hardness, the porosity, and the potential for etching. Here are two suggestions on how to find out the answers to these questions firsthand:

1. The Key Test

If you’re curious about the hardness of a certain stone, try using a car key to test its scratching potential. On the back of a sample or on the very outer half inch edge of the slab (this area is usually discarded by the fabricator anyway, but it is polite to ask permission first), drag your key firmly down the surface and see what happens. The more types of stones you key, the more familiar you’ll become with the varying hardness of stone. Whether it scratches easily, or not at all, it’s up to you to decide what you can live with.

2. The Ketchup Test

If you’re curious about whether a stone will stain or etch, take a small sample of the stone in question home. Try leaving a few drops of ketchup on the unsealed polished surface of the sample. Wipe off the spill after 15-20 minutes (about the time is takes to clean up after making dinner) and look for two things: any sign of a red stain (this indicates porosity and staining potential), or any spots where the surface is no longer shiny (this indicates the level of calcite content – the more calcite, the more the surface will etch). Next, try sealing the stone and repeat the experiment to see how much of an effect the sealer has on the stones’ natural qualities.

People will tell you all kinds of things about what stone is “good” or “bad” for your project, but when it’s all said and done, you’re the one that has to live with it. If you love marble and don’t mind its natural properties, go for it! If you’re looking for granite that won’t scratch or stain or etch easily, test it out for yourself to be sure! Only you know what constitutes a “good value” for you.