Rock Identification

[Chris_W]

I found this on a beach in Greece when I was a kid, and have lately been wondering what it is. I can't seem to find close enough pictures online. Any ideas?

 

[faribo]

calcite

 

[IAMZIM]

I concur with faribo. Calcite, with possibly some limestone matrix. Put a little bit of vinegar on it, it should bubble. Being calcite it may also glow under a black light, either long wave or short wave.

 

[A2coins]

Now that's a cool looking rock