I've never seen it anywhere else, what do I have?

[finksmart]

Got it as "Blue Ring" but what is it really?

 

[finksmart]

Found it. It's called Angel Halo:

http://www.pacificeastaquaculture.c.../ShowProductCategory.aspx?CategoryId=83#T6-98

 

[zcwrx]

I've seen them called kryptonite

 

[jadeguppy]

kryptonite are more purple, less red