A lot of home/property insurance policies have a clause that covers jewelry. Do you inform your insurance carrier every time you purchase an expensive piece? If I were you, I would. Jewelry depreciates greatly so you want a record somewhere that can help you in the even the item is stolen.
I've never had jewelry that was expensive enough to worry about. I have, in the past, had to claim a piano as an additional item on my insurance. I have also added a MacBook Pro in the past, as it exceeded the single item value limit that State Farm has. If you have any item, jewelry or not, that has a lot of value it has to be claimed or listed on your insurance otherwise you will not be able to get reimbursed for it, if you would need to file a claim.
I actually had an additional policy specifically for the jewelry. Diamonds go up and down often, but usually up. Insurance is a scam though. I had a $10,000 ring that was appraised right before it was lost in a flood. The insurance only gave me $4500 because that is what their jeweler who never saw it said that it was.