What are those white dots on my white marble?
Have you ever wondered what those white dots are on white marble? You sometimes see thousands of them in high-traffic lobbies. Although you can see them, you can’t feel them. What are these mystery dots?
If you were to take a hammer and hit a piece of white marble, it would leave a white dot that stone professionals call stuns or crystal fractures. I theorized that marks like these are caused by an explosion of the calcium crystal within the stone. I reached out to Kendall L. Hauer, Ph.D. of Miami University, Department of Geology and Environmental Earth Science to verify my theory. He explained, "When any color of marble/limestone is crushed, it will take the form of a white powder. Essentially, what you are seeing is the "streak" of calcite, which is always white. It is always white because powdering limestone essentially negates the effect of any color-causing impurities."
So, in other words, the impact of a sharp pointed object, such as a woman’s high heel, will crush the calcium crystal, leaving a white dot. Now you know.