There is some kind of very tiny dark purple moss or something strange growing on the surface of the soil covering my entire garden. It scrapes right off but it's everywhere and getting thicker. What is it? Is there something specific that causes it? And is there a way to get rid of it or is it harmless? I have never seen anything like it before. Please help. Thank you.

to NGA

In order to help you, we need a little more information. Can you update your info to include your location? And can you take some photos of this purple stuff?