Any independent jeweler can help you out.
I will say one practical consideration is that diamonds are really hard and don't get scratched. You may want to consider hardness for any replacement gemstone (rubies and sapphires are the next hardest).
Any independent jeweler can help you out.
I will say one practical consideration is that diamonds are really hard and don't get scratched. You may want to consider hardness for any replacement gemstone (rubies and sapphires are the next hardest).