Why would ANY jewelry store replace a large stone for free? You could just be at home, popping out stones and selling them loose and then raising hell on the internet and filing false claims to make a profit. NO jewelr in the entire world would replace a large lost tanzanite, or diamond or nay stone for that matter simply because you claim it fell out. As far as feeling what you refer to as Burs, if your hsuband hit his ring against something hard enough to shake the stone, it would also affect the integirty of the metal around it. Gold and silver are soft metals, not meant for rough play.
In response to saying the stores give "kickbacks" you are wrong. It is a paid for promotional program. thats called advertising, not kickback. Kickback implies something shady and under the table. Something done illicitly. if you read your cruise offered guarantee, it clearly states the parameters of the advertised program. Do you buy any product with brand names? Coca Cola? Toyota? Nike? Guess what? Those all advertise to gain customers. Does that make them bad, or false? NO! Have you ever sat down with a car salesman or insurance salesman and had them explain what they personally are being paid before you discuss the price of the goods or service? No, you havent, and thats why it isnt a kickback, or a scam. You should read things before you sign them, and if you dont agree then dont buy it. I ONLY purchase watches and jewelry from the map mentioned stores on cruises, and someday, when you shop at one off the map and your diamond turns out to be glass, or your tanzanite to be an iolite, youll deserve it.