Does anyone know what this is?

[+Hydro]

It is a hard coral and is shaped like a cup.

[reefman]

Turbinaria Cup Coral

Stephen

[+Hydro]

Thanks

[Timfish]

Turbinaria Cup Coral

+1, most likely Turbinaria peltata. I've had one in one of my tanks for 6+ years thats maybe doubled in size but has never extended it's polyps

[+Hydro]

I think that you are right, I googled that and came up with a picture that looks very similar to mine but just a different color.

http://farm4.static.flickr.com/3012/2846789413_33cda1b248.jpg

What is the value of these corals? Are they rare? I see that some are cheap and some more expensive but there aren't very many for sale online (the particular species that I have), I'm sure it depends on color and avaiability.

To frag do you just cut it or break off a piece?

[Timfish]

I don't think they're rare, just not really sought after 'cause they're not a particularly pretty coral. Breaking or cutting it up will work to start multiple colonies. They can get really big and heavy, they have a very solid skeleton. Here's a picture of one with the polyps fully expanded. I'm guessing it weighs in the 25 - 30 lb range and is at least 13 -14 years old, the diameter I'd say is increasing about 1-2 inchs a year. Tank is a 200 with 8 39W T5's and 4 54W T5's (The one I mentioned above is in a different tank but with the same filtration and lighting, go figure).