Monti?

[Rybren]

I picked this up a month or two ago. There are no visible polyps that I can see.

I suspect that it is a form of encrusting Monti, but not really sure.

 

[James55r]

Kinda looks like a montipora undata but most have visiual very tiny polyps

 

[Eckolancer]

Looks more like montipora confusa or montipora spongodes

 

[Hawain_Rob]

Idaho grape?

 

[Rybren]

Thanks guys, this has given me a good starting point. Looking at images online, the Undata is the closest match. From what I've seen, I guess that the Idaho grape is a variety of Undata, but mine is blue rather than purple.

Thanks again.

 

[Salty1962]

Montipora Spongodes would be my guess. Hard to tell from pic.