Advise on 18k Estate 4 Prong Marquise Blue Diamond

[char_livermore]

I need some advise on this 18k Marquise Blue Diamond it is marked 18k 4 prong 1.5 stone marked inside of ring. The question is this blue diamond changes different colors in direct sunlight from gray to a light sky blue indoors it is darker but never loses its color The ring was bought from an estate I have no GIA report but 2 local jewelers said it was a fancy color.The ring has carbon through out ring and too the ring tests diamond.

Could this be a real blue diamond natural mined and or a diamond fluorescence that emits a strong blue? Any insight ?

Your help would be appreciated Char

 

[DiamondBrokersofFlorida]

It doesn't look like a blue diamond to me. You might be describing flourescence.

 

[char_livermore]

Talked to 2 local jewelers today one being in business for 50 years he said it was a fancy light with gray tones he also said he has not seen one in years told me not to sell it. The other jeweler told me it was a fancy light she took it outside to view it in the sun so now to the GIA for full report. Char