What are you talking about?? A Guide to a Jeweler’s Vocabulary

We thought it might be helpful to offer a little glossary of words and terms we use when designing and making jewelry. If there’s something we missed, let us know!

Gemstone Terms:

cabochon:  a gem that is cut with a smooth, domed top and a flat (or slightly domed) bottom.  It is less sparkly than a faceted stone, but offers a soft and luminous look that feels more casual.

carat:  a unit of measurement to express a gemstone’s weight.  One carat equals 0.2 gram.  “Carat” can be applied to diamonds as well as colored gems.  It is abbreviated “ct”.

facet/faceted:  a flat surface on a gemstone, created during the process of turning a rough mineral into a brilliant one.  A faceted gem typically has many facets, both on the top and the bottom.  The traditional round, brilliant-cut diamond has 58 facets.

girdle: the widest part of a faceted stone, often quite thin, and is the part that must be captured by prongs or a bezel for a stone to be secure.

melee:  very small diamonds, roughly 0.005 to 0.15 carat.  They are often mistakenly called “chips” which implies that these tiny stones were simply hacked off the mother rock.  Not so!  Each melee diamond has its facets carefully cut and polished to enhance its brilliance.  They vary in quality, like everything else, and may or may not be suitable for repurposing in a new piece.

natural:  a gem made by the earth.  But also, a gem that has not been treated in any way besides having been mined, cut and polished.  A gem unenhanced by heat, radiation, dye, oil, fillers, or any procedure to improve its color or clarity beyond cutting and polishing.

rose-cut:  a style of gem-cutting that is like a blend of faceted and cabochon.  It has facets on the top, and is flat on the bottom.  Picture half a golf ball and you’ll get the idea.  The shape of a rose-cut gem can be round, square, oval, or any freeform shape the cutter desires and can execute. (They’re talented that way!)

synthetic:  a gem made by humans, not nature.  For example, a synthetic sapphire is chemically identical to a natural, came-out-of-the-ground sapphire, but was created in a lab under highly controlled conditions.  Many gems are synthetically made, including amethysts, emeralds, opals, rubies, and even diamonds.

tcw or ctw: total carat weight or carat total weight, respectively.  The collective weight of more than one gemstone in a piece of jewelry (or parcel of loose gems).  For instance, if a diamond channel band has 20 small diamonds, the description might read “0.42 ctw”, rather than list the exact weight of all 20 stones.

Precious Metal Terms:

alloy:  the combination of a precious metal with a specific percentage of other metals to make it suitably strong for jewelry wear. For instance, pure gold is combined with copper and silver to create 14k gold.  Specific recipes for various alloys are often proprietary and kept secret by metallurgists.  Therefore, it is possible for two different alloys of 14k yellow gold to look different in color.

karat:  a way to describe gold purity, expressed in parts per 24. (In the U.K., they use “carat” for both gem weight and gold purity; e.g., 18 carat gold (75% purity) and 1.09 carat diamond (weight)

24k: pure gold, unalloyed with anything else.  It is 24 out of 24 parts gold.

22k:  an alloy that it 22 out of 24 parts (91.7%) pure gold. The other 2 parts per 24 (8.3%) are usually a combination of pure silver and pure copper.

18k: an alloy that is 18 out of 24 parts (75%) pure gold, with the remainder made up of other metals such as silver, copper, nickel, palladium, zinc, and/or silicon.  It is the composition of this non-gold 25% that determines the color of the gold alloy, for instance, whether it becomes yellow gold, white gold, rose gold, etc.  We work primarily with 18k gold alloys because of their higher purity, beauty and better workability compared with lower karat alloys.

14k: You guessed it: 14 parts pure gold, and 10 parts other metals.  This is the widespread standard for karat of gold jewelry in the U.S. 

platinum:  a naturally dense precious metal with a silvery grey color.  Not to be confused with white gold.  Platinum is nonreactive and hypoallergenic, and is used in a higher concentration in jewelry alloys.  Platinum jewelry contains 90-95% pure platinum, and will weigh about 30% more than a piece of gold jewelry of the same volume.

 rose gold: also called pink gold or red gold.  This alloy contains a higher amount of copper than yellow gold.

 white gold: a gold alloy that contains a “whitening” metal, either nickel or palladium, in an attempt to mask the true yellowness of gold.  White gold can never be as white as silver or platinum, because it is predominantly a yellow metal.  Many jewelers plate white gold with a metal like rhodium to give it a bright white finish.  We don’t, as the setup is toxic and the finish is temporary.

Jewelry Terms:

bezel:  A bezel is a rim of metal that is pushed around the entire circumference of a gem to secure it.  A gem that is bezel-set is held mechanically by the bending of metal over the stone’s girdle. No glue is involved!

bail:  the mechanism by which a pendant can be hung from a chain.  It could be a simple loop soldered to the top, or an integrated part of the overall design.

prong:  A prong is a thin finger of metal that holds a gem on one of its facets.  Because each prong only secures a small part of the gem, prongs are always used in multiples, with four and six being the most common.  Prongs must be checked regularly for wear and tear, and could require maintenance several times over the lifetime of a ring.

setting:  the part of a ring that holds the stone(s).  For example, the whole bezel or prong assembly. 

shank: the part of a ring that goes around the finger and is not what holds the stone in place.  In other words, the band part of the ring.

shoulders: the part of a ring on either side of the setting where it meets the shank