How to clean a granite marker

Factual Questions
1

I want to clean some lichen from my grandparents headstone. It’s growing in the rough engraved areas. I was thinking some bleach water and a toothbrush would be good for this. Bleach water will kill the lichen and help with it’s removal. Is the bleach going to harm the granite? I don’t think it’s strong enough to etch it, is it?

2

Bleach will not etch granite, no. In fact, I can’t think of a chemical that will etch granite besides hydrofluoric acid, which they use for etching glass (granite is about 70% quartz, which is in turn the same material as glass).

Since you can’t exactly buy HF at your corner store… I’d say you can use anything. I would recommend SimpleGreen or trisodium phosphate; those may break up the lichen more effectively.

LL

3

Thank’s for the answer.

4

Muriatic acid is the common item used for cleaning stone. It is available in hardware stores. Follow the directions on the container.

5

Thanks for the input.