Before you buy anything, learn some fundamental information.
For example, if you buy a diamond ring, you must know what 4C is, which is essential knowledge about diamonds. 4C is an abbreviation that means: Cut, Color, Clarity, and Carat Weight. Simply speaking, you may want to know how many levels each C has, how people define these levels, which level you are looking for, etc.
Research can help you qualify the gem you want to buy and better understand which market price is considered fair.
All your doubts are because of TRUST, and nothing is wrong with that. So, finding a site with a good reputation can help you a lot. First, look for online stores which have been established for at least five years. The more history it has, the more trustworthy it would be.
Make sure you can contact the sellers, either by email or phone. Usually, those owners are experts in their respective industries, they would gladly share their knowledge with you and answer your questions. If the seller does not reply, it is probably not a good idea to buy from them.
Searching for posts on social media might be another way to help you to confirm their reputation. You can see the comments from other customers and the brands’ number of followers.
Due to the lack of dealing with real jewelry, you will probably get something you didn’t expect at first. Wrong size, shallow cut, it looks different from the images online, etc. These problems are hard to avoid, requiring you to pay attention to the Return Policy before you buy. Make sure the policy is guaranteed! Online sellers usually offer 30-day returns, depending on other situations. In addition, online jewelry sellers provide multiple payment offers, such as PayPal, Credit Card, Debit Card, Alipay, etc. It brings us much convenience.
After you find a respective site, make sure they offer a secure payment system. All of the payments should go through a secure payment system, and a respectable carrier company should do the delivery.
Unless you are buying antique jewelry, you must make sure there is a certification coming with it. Usually, those respectable jewelry sellers will offer it.
Ask the seller if the diamond has been certified by GIA (Gemological Institute of America). Usually, diamonds with GIA certification are more expensive than those with other certifications.
One of the advantages of buying jewelry online is that you can read reviews from other customers. You may get more honest information (which the seller won’t tell), even some problems you ignored from the reviews.