Yes!
'Good' is a judgement and you are the judge. A 'good' diamond could be a perfect, flawless, diamond, as in a 'good' investment. Or a 'good' diamond could be a family heirloom, worn by several generations of fabulous women.
It is good against Fire, Ground, and Rock.
Have a talk with him about it, and present it as an option only. He may love the idea. If he doesn't, no problem. He may feel strongly that the engagement ring should come from him. He is, after all proposing marriage, and offering something of himself in the form of a pledge. It would be odd for him to offer her something that is, in a way, already hers. You can always offer the heirloom diamond to your daughter as a present-- maybe on the first anniversary. My opinion, however little it is worth, is that the engagement is the first of many things that couples take on together. Even if what he can afford pales in comparison to the heirloom, it is probably more important that the ring come from his efforts.
Ground.
scratch it against glass if the glass scratches its diamond
Diamonds polishing is the process of rubbing a gem-quality diamond against a diamond-encrusted sheet, to render a facet flat and properly angled.
Diamond is the hardest natural mineral known. Wear could show on the edges if the diamond rubbed against another diamond.
Fire :)
The 2013 Chevrolet Black-Diamond-Avalanche has a 6 yr./ 100000 mi. warranty against rust.
scratch the diamond against glass...if it scratches its real if it doesn't its fake
Man Against Crime - 1949 Death on the Diamond 4-39 was released on: USA: 17 July 1953
As diamond is the hardest natural mineral on earth, theoretically, only diamond can cut a diamond. But, diamonds are also cut by lasers. Diamonds are cut and polished on diamond wheels. They are held against a rotating plate which is made from hardened steel infused with diamond dust.