Disclaimer...I am not a gemologist.
All kinds of games are played in the gem business. Unless things have changed, if you ask for topaz, for example, they can sell you yellow quartz (citrine)...to get topaz, you have to ask for “precious topaz”!
Also, I imagine that you’re speaking of artifically created blue diamonds, not natural ones. The Hope Diamond, for example, will fluoresce red from the boron content, unlike diamonds that are turned blue by radiation/heat treatment.
In any case, I think that blue diamonds are still readily available in the US.
No the BLue diamonds that I bought in a formation are natural..
Not Topaz but seablue Diamnonds.
I bought them as a personal thing to remind me everyday of my faith and uh hum life dedications.
It was odd though I was invited and then called to say We do not carry any Blue Diamonds in the Collection or State Side.
So First thought was is this a Political cause.
Well I can now buy 10 tanks in my SUV/RV and I wont be dawing any earrings.
Oh well Godiva Chocolates still has a 50% off sale.