I'm not big on the knife edge shank but the halo seems fine (pics are kind of blurry though). Do you like it (are you going to be the
person wearing it?)
They might. But they might not. It looks like a mass produced setting. Those vary in quality from great to not so great. I can't tell you more from the pictures you posted. If you are concerned take it to an independent (this is key, cannot be affiliated with any jewelry store) appraiser and ask them about the quality of it.
I can tell you it doesn't look clean. I would keep it clean.
It's been sold an auction so I can bring it anywhere . I like the size and shake on my finger. I was thinking of getting it and then getting it services and cleaned .
Will it be hard to get a wedding band to sit flush with this ?
A DIAMOND CLUSTER RING.
9ct white gold, modern in design, featuring a central brilliant cut diamond of approximately 1.38ct, claw set in four bead claws, grain set within a fine frame of tiny brilliant cut diamonds, completed on a knife edge band with small diamonds running along each side, totalling approximately 0.18ct, merging to a plain band at reverse.
Yes, you do need some education before you waste your money. We have an entire forum called Show Me The Bling on here. Full of nicely cut diamonds in well crafted settings. Spend a week looking on there. And on here click on the stones we recommend for others.
We are happy to help you find something worth spending money on, if you don't want to do that. Tell us your budget and what you are hoping to get for it and we'll do what we can to help you get the best your money buys.
That last one isn't good either it's a flat top early modern round brilliant.
Also, i forgot to answer one of your questions. Knife edge is a style. It's not a measure of quality. I've seen some amazingly beautiful knife edge pave settings.