What would cause this?

[skphotoimages]

My husband and I were recently shopping for an upgrade diamond. We were at a B&M and the lady ( who we personally know) pulled out a diamond. It was blue, not quite as blue as blue topaz, but definitly blue. It wasn''t marked as a blue diamond though, and it cerrtaintly wasn''t priced as one. She couldn''t figure it out either. There was no cert to look at. Is it possible for blue fluorescence to be this strong?

 

[DiamondExpert]

not common, but possible...depends on how much UV there was in the lighting.

 

[skphotoimages]

Whey were those trick store lights

They were REALLY white track lighting. I guess there could have been uv in them. The ring was 1.5-1.75 ct vs2-SI1 clarity. It was SOOO pretty. It think it was 4 or 5 thousand dollars. it didn't look milky though. Weird. I only asked because if it couldn't be anyhting other than a blue diamond, I think I would buy it for a second ring at that price.
Thanks.