When it comes to securing your jewelry and other valuables there are some basic rules that apply. If it is valuable and you are concerned about it being stolen then you can always get it insured and this will offer some protection. Having a reliable burglar alarm installed on your home is something that you will want to seriously consider also. Alarm systems and services have become more affordable then they used to be and they also offer higher levels of protection.
Have a secure place to keep your jewelry in your home such as a safe is also a good idea to consider. A good quality safe will protect you from fire as well as theft and they are not as expensive as you might think. For as little as a couple of hundred dollars you can get a nice safe at your local home supply chain store. Even if a safe looks impregnable to you, that doesn't necessarily mean that it is so, because a strong man with a sledge hammer and an industrial pry bar can get into almost any commercially available safe if given enough time.
Time is the key word with regards to safes, because the more difficult that a safe is to move and breach the longer it will take to remove or breach it. Consider having your safe bolted to a wall or the floor and a call to any handyman service can get this done. Once you have a reliable alarm system in place and a nice safe bolted to the floor of your closet then you can rest assured that your valuables and jewelry are safe. Until then if you are lacking the alarm in particular you are taking chances that you really shouldn't be taking.