Some people may say, "Oh, I've got plenty of property coverage on my homeowner's policy." But, keep in mind that most such policies have a separate limit on "collectibles." That limit is often quite low, $5000 is typical.
You might say, "Well, $5000 may not cover you, Mr. Balisong Collector, but it's plenty for my modest collection." But, don't forget that that $5000 is for ALL "collectibles" in your house. If you have a total loss, if the house burns down for example, that $5000 is all you're gonna get for ALL of your collectibles.
You might say, "Well, I don't really collect anything else." But the word collectible in your insurance policy means anything with value based on age, uniqueness, scarcity, etc. It's a broad category. Even though you think of it as, "the stuff we use when company comes for dinner," your good silverware could be considered collectible. Jewelry can easily become a collectible. Just because YOU don't consider YOURSELF a collector of a certain item, just because you don't think of what you own as "a collection," doesn't mean that it's not a collectible for insurance purposes.
Another limit to be aware of that's on a lot of homeowner's policies (not all, but a lot) is a separate limit on firearms. Guns are such a common theft item (and they're also commonly involved in insurance fraud) that insurance companies often include special limits on them to limit their losses. A common limit is $500. Yes, just $500. But, a single pistol can easily cost well over $500. So, if you have multiple firearms, as many folks in this forum do (some of which might fall under collectibles), you might want to check your policy for that limit too.
Jewelry is another item that just about always has a separate limit. It's usually pretty high. But, if the wife's got some nice pieces, you might want to double-check your limit in this department too.
Insurance companies will adjust all of these numbers for you, for extra cost. If you own several guns that are together worth maybe $2000, just talk to your agent and for a few dollars a year, they'll probably up that limit for you.
If you own a proper safe, don't forget to tell your insurance agent about that since you may qualify for a tidy discount. Of course, the safe will have to meet the insurance company's requirements. That usually includes a requirement that the safe be bolted to the house's foundation. But, be sure to ask regardless of what safe you've got; you could get some discount.
There is special insurance for collectibles. Chubb Group is a big name in this business. But, until you start decorating with original Monets, you're probably gonna be best off financially to just extend limits on your conventional home owner's or renter's policy.