No, you really can't tell.
You certainly can tell the difference, just not visually.
The crystal structure is different. Synthetic diamonds also have a laser inscription required by US law.
The GIA recognizes them as diamonds.
Once again, as the article I posted above clearly shows, the GIA now GRADES synthetic diamonds while at the same time permanently marking them even further to assure there can be no deception. They also give them a different color classification certificate so you cannot use their grading to try to dupe unsuspecting people.
They are the exact same as mined flawless diamonds.
Once again, no they are not. They are synthetically produced instead of bein naturally made.
The difference between natural and synthetic diamonds may not matter to you, but it certainly matters to their value on the open market.
I'd ask her about it, if I wasn't planning on surprising her (if I was, well, I make it a hypothetical situation). A ring is basically a social contract. It's a human thing. Trying to take a one size fits all approach to that is just pointless. Some girls want big rocks. Others dislike the idea of blood diamonds. Others however, want tradition. And really, it's a gift to her. Even if you think it's silly, she deserves what she wants.
I agree completely. Deliberately deceiving your future wife with an item that she can easily find out the truth by visiting any jewelry store is probably not the best way to start a long-term relationship. When cubic zirconia became really cheap a few decades ago, a lot of men did just this. I bet a lot of them are divorced now.
This is excellent. Now that the West can produce these cheaply it should secretly flood the gray market with these real diamonds whose value is dependent on the buyer's knowledge of its source. The devaluation of the diamond will mean that the West can stop funding those African warlords so that they'll have to use spears and stuff instead of Kalashnikovs and RPGs. Dare I say it? It will be awesome.
Ironically, that is exactly what won't happen due to the laws enacted to protect people from exactly that sort of fraud.
You may not personally agree with the way DeBeers does business. I certainly don't. But this should have no effect on the overally diamond market until everybody decides to no longer purchase natural diamonds for social reasons. They certainly haven't shown much of an inclination to do that yet. After all, diamonds and other rare natural stones which are typically mined by exploited people aren't necessities.
And take a look at the fur industry. It wasn't high-grade fake furs that largely doomed them. It was declining demand created by a hostile reaction by many. If you continue to wear synthetic diamonds, you are actually supporting instead of hurting the efforts to end such rampant exploitation because nobody will be able to discern the difference without a loupe.
SHows how much of a cheapskate I am.
545.67 carats of pure Love! 
