Hi, I want to create a 'rustic' polished concrete floor in my bathroom, similar to the attached image.

It's very similar to 'acid stained polished concrete' but less refined. I've lost touch with the person who did the floor in the attached image but I remember him telling me that it's an old Roman technique involving lime.

There is also another much darker rustic polished floor technique that I would like to explore for my bathroom. It's common in France and Spain for countertops and sinks and it has a very dark (almost black) rustic texture. I think it involves diamond polishing a mixture of cement and earth and adding a black ash product to create the dark effect, but I can't find any examples online

Do you have any idea what the technical names are for these techniques are so I can find more examples and instructions on the net?

Cheers!

Leao