Much of learning about old jewelry, as with any subject, involves learning the lingo. Terms that crop up often in the antique marketplace include:
Art Nouveau: the style that flourished between roughly 1890 and 1914, characterized by burnished yellow gold, soft enamel colors and undulating, curvy shapes. Common motifs were flowers, plants and female figures with long, wavy hair. Many consider René Lalique, who designed jewelry before he got into frosted glass, the ultimate Art Nouveau artist. Click here to view an Art Nouveau brooch.
Art Deco: the streamlined style of the 1920s and '30s, characterized by flat geometric shapes and bold color contrasts (red/black and green/blue are typical combinations). In particular, the jeweler Cartier is known for designing primo Art Deco.
Retro: referring to the style developed in 1940s and '50s, characterized by wavy lines and large stones (rubies and aquamarines were favorites), often set in rose gold. Wallis Simpson, the Duchess of Windsor, popularized this bold, solid look.
Old mine cut: a 19th century method of faceting gemstones - usually diamonds - that prevailed up until the early 1900s. Because they have fewer facets, old mine cut stones twinkle differently than their modern counterparts, exhibiting more of a subtle sparkle than a fiery flash.
Cabochon: a gem that has a smooth rounded surface instead of being cut into facets. It gleams rather than sparkles.
Paste: not the gluey stuff, but pieces of glass cut and colored to look like gems, form of imitation that dates back to the 17th century. Though technically costume jewelry, many paste pieces were often exquisitely made and set into precious metals.
Parure or suite: traditionally, a full set of matching jewelry, comprised of a necklace, two bracelets, a ring, earrings, brooch and sometimes a tiara or other hair ornament. A demi-parure is a less elaborate suite of (usually) a necklace, earrings and a brooch. However, nowadays three or more coordinating pieces, designed to be worn together as a set, are often referred to as a parure.
Millegrain: a metal setting for stones decorated with tiny, raised beads. Especially popular in the early 20th century, it's making a comeback today-often to give modern jewelry an antique look.