Please bear with me, as I am a total and complete novice. I never owned a diamond, and am now looking at engagement rings. Tonight, at a major dept. store (where I swore I would never even look), I saw a beautiful "estate" ring. The saleslady was very helpful (I hope). She said it was OEC. Now, I never heard of that till that moment. She told me she felt the color is "D", and the clarity VS1. It is .45 carat. Also, I remember her mentioning an AGS #, but I didn't know what that was, and forget what she said. We compared it to other rings in the case, and all concluded it "sparkled" way more than others. She kept saying it had "fire", but I didn't realize she was using an actual term of art! Anyway, the price (with all their "markdowns", discounts for using the credit card, etc) comes to around $750.00 She suggested I change the setting as it hides much of the stone (the prongs are wide?), as well as being set too deep. I love the ring, but how can I know if it is truly what she says it is? She said it is definitely "heirloom", and not a new Old Cut. How can I know for sure about anything she told me?