I’ll tell you what I used to do when customers were torn between two pieces of jewellery.
I would mix them up and hold them behind my back. I asked them to pick a hand. It wasn’t to make them take the one they chose but to ask if they were happy or disappointed with the choice. It concentrated their minds.
You could write “emerald” and “sapphire” on two pieces of paper and pick one out of a hat, as it were. It might help you see where your heart lies.
Both are beautiful by the way, I might “casually” share this with DH, it’s our Ruby in a few years…. Just saying!