Formaldehyde
Both Fair And Balanced
When a woman shows all her friends her flawless 2 carat diamond solitaire engagement ring, she is effectively saying "My future husband just spent over $10K on me. I think he's really committed to marrying me." She isn't saying "I think my future husband just saved $7500 by buying a synthetic diamond instead of a natural one. Isn't he a smart shopper since none of you can tell the difference without a loupe or a microscope?"
But whatever you do, don't lie to her about it. If she wants to deceive her own friends by not explaining it isn't what they think it is, that's her business. Eventually, she may very well find out the truth when she needs to have the crown repaired or have it cleaned.
I think you are a lot better off buying her some other stone, myself. There are many very attractive gems that don't cost nearly as much as diamonds, sapphires, and rubies do.
But whatever you do, don't lie to her about it. If she wants to deceive her own friends by not explaining it isn't what they think it is, that's her business. Eventually, she may very well find out the truth when she needs to have the crown repaired or have it cleaned.
I think you are a lot better off buying her some other stone, myself. There are many very attractive gems that don't cost nearly as much as diamonds, sapphires, and rubies do.