1. Invest in a loupe!A loupe, that special magnifying tool you often see jewelers pull out and place on or near their eye, is a must if you hope to make a habit of buying vintage jewelry, whether in person or virtually. Here's why: the closer you examine a piece of jewelry, the more you notice, both good and bad. You can use a loupe when considering an in-person purchase, to notice details that help you make your decision, or, if you purchase jewelry online, you can examine it after purchase to ensure it matches the seller's description. Not thrilled with the idea of spending money on a loupe? Any jeweler worth his/her weight will have a loupe on hand for you to use if you are purchasing jewelry from a brick and mortar store. Simply ask them.
2. Look closely & pay attention to detailsSo now you've got your loupe, or even if not, it's time to look closely at your piece, in hand or through photos from an online seller.
First - look for hallmarks of any kind.This antique ring from 1921 has a purity mark of "22k". There are usually two types of hallmarks, although for European-made jewelry there may be more. One type of hallmark is for the metal itself, called a purity mark, such as "sterling" or "14k" (gold) stamps. While a metal mark isn't 100% dependable - sometimes items were stamped as solid gold, for instance, and they may just be gold plated - a metal mark is at least a starting place to begin to uncover the story of your piece. Next, look for a maker's mark; maker's marks tell you who made the piece of jewelry. Like a fingerprint, the hallmarks in this ring tell you that it's 15k gold, and was made in 1870 in Birmingham, England.
This too isn't a perfect clue, as many times American made jewelry wasn't hallmarked in any way. European jewelry, however, has had a required hallmarking system for centuries, and some European pieces will even have date marks to tell you exactly when the piece was made. There are many books out there to help you decipher your maker's mark, and of course there are also famous jewelry designers' marks to keep on the lookout for when purchasing pieces - Belais of the 1920's or Ostby & Barton of Titanic fame, for instance - which will not only immediately date a piece of jewelry, but often can make it more valuable as well.
Secondly - look at the condition of the vintage jewelry.
Remember that all vintage jewelry has years, decades, perhaps even centuries' of wear. So don't expect a perfect piece; in fact, too perfect of a piece may indicate it's reproduction jewelry. The wear to a piece is its story, its imprint of memories. However, it's important, particularly if you are making a bigger investment, to look closely at the condition of the jewelry, and/or the condition report and photos which a seller provides.
When it comes to jewelry, some of the usual suspects in terms of condition issues which are easily visible with the naked eye (or a loupe) include chipped, cracked or badly scratched stones (diamonds can withstand quite a bit more of wear, so colored stones and white sapphires, etc, are those that most exhibit surface wear), loose stones (tip: shake the ring next to your ear and listen for the stone jostling around!), missing stones, very thin or broken prongs around a stone, chips or cracks in enamel, an overly thin band, or broken filigree. Many condition issues can be fixed by a reputable jeweler.
3. Know your eras
You don't have to know everything about jewelry to buy jewelry - it takes more than a lifetime to learn it all! Like everything, however, some knowledge can go a long way. In the case of jewelry, you'll want to do just a bit of research to understand the different jewelry eras - Georgian, Victorian, Art Nouveau, Edwardian, Art Deco, etc. - as that information will not only help you understand what you like most, but it will also help you pick out those hidden treasures, and to know if the information you're being given on an item from a seller is accurate. Buckle motifs were common in the Victorian era. Similarly, the use of black enamel with a single pearl in this locket - an indicator of mourning jewelry - the evidence of age on the clasp and hinge, and the age of the photo inside, help you date it to the Victorian period. For instance, if you find a platinum ring and it's being sold as a Georgian ring, that dating is inaccurate, as the Georgian period was from 1714-1837, and platinum wasn't in widespread use until the early 1900's. Silver was a more common setting material for the Georgian period. Or, you may find jewelry that, upon close inspection, has a piece of cloth, or even hair, within it, a common bit of artistry from the Victorian period. You can work backwards as well - that's often how I learn jewelry best! - by Googling a particular feature, hallmark or other characteristic you've found on your mystery jewelry. The cutouts and curves of this piece are an Art Deco feature which help you date it.
4. Purchase from a reputable seller
Particularly when purchasing online, but even when purchasing in person, know as much as you can about the person selling the item. Reviews on sites like Etsy or Ebay - you'll see our shop has a 5 star review status! - or well established jewelers or shows in your area, give you a good idea of the customer experience, and whether or not that seller can be depended upon to sell good, accurately described jewelry. Never hesitate to ask the seller questions as another source of information; reputable sellers will be happy to answer your questions and even send you additional pictures or videos if they sell online. When purchasing higher-end jewelry with stones, you should look for sellers who are certified gemologists with GIA, or are on that path (such as myself), or who have their jewelry examined and assessed by those who are GIA certified. Without this knowledge, it can be impossible to accurately identify some jewelry, particularly the stones, as some differing stones can look exactly the same to the untrained eye. Buy from stores that have a good return policy, and clear communication around purchases, so that you can feel secure in your purchase. Lastly, the best part about a reputable seller is that s/he is usually a font of wisdom about jewelry! Ask lots of questions, and learn as much as you can.