ASHEVILLE, N.C. (828newsNOW) — That old ring sitting in a jewelry box could be worth more than its sentimental value — or it could be worth considerably less than you think.

Figuring out what jewelry is actually worth can be tricky. A piece’s age, appearance or family history doesn’t necessarily determine its monetary value.

To help consumers understand what they’re looking at, D.C. Creasman Jewelers explains some of the basics of determining the value of gold, diamonds and older jewelry.

What do those karat stamps mean?

One of the first things to look for on gold jewelry is a small stamp indicating its karat purity.

The most common markings are 10K, 14K and 18K.

The number refers to how much of the metal is pure gold. Because pure gold is 24 karats, 18K gold is 18 parts gold and six parts other metals, while 14K is 14 parts gold and 10 parts other metals.

That also means a higher karat number generally indicates a higher gold content.

But the stamp isn’t necessarily the final word on a piece’s value. Jewelry can be damaged, altered or improperly marked, and other factors can affect its value.

How can you tell gold from gold-plated jewelry?

Gold-plated jewelry has a layer of gold applied over another metal.

That can make it look like solid gold, particularly when it’s new.

Over time, however, wear can expose the underlying metal, especially around areas that receive frequent contact, such as the edges of rings, clasps and bracelet links.

Consumers should look for markings that indicate whether a piece is solid gold, gold-filled or gold-plated. Terms such as “GP” can indicate gold plating, while “GF” generally refers to gold-filled jewelry.

When in doubt, a jeweler can test the metal rather than relying solely on appearance or a stamp.

What makes a diamond valuable?

The familiar 4Cs — cut, color, clarity and carat weight — are among the primary factors used to evaluate a diamond.

Carat refers to the diamond’s weight, not necessarily its size.

Color measures how much color is present in a diamond. For traditional white diamonds, less color generally means a higher grade.

Clarity refers to internal and external characteristics, often called inclusions and blemishes.

Cut describes how well the diamond has been shaped and polished and how effectively it interacts with light.

The 4Cs don’t tell the entire story, though. Two diamonds with the same carat weight can have substantially different values depending on their cut, color, clarity, certification and other characteristics.

Does an old piece automatically have more value?

Not necessarily.

Age can be important, particularly when a piece has historical significance, is considered antique or represents a desirable period or style.

But an old piece isn’t automatically valuable simply because it has been around for decades.

The value may instead come from the materials, craftsmanship, designer or maker, rarity, condition and demand among collectors.

A piece of older jewelry may also have sentimental value to a family that far exceeds its resale value.

Before you sell, get it checked

For anyone cleaning out a jewelry box or considering selling an inherited piece, experts generally recommend having valuable or potentially valuable jewelry evaluated before making a decision.

That can be particularly important with older jewelry, unusual pieces and items whose value isn’t obvious from their appearance.

A professional jeweler also can help determine whether a piece is solid gold, plated or made from another material and can evaluate gemstones and diamonds.

And remember: sentimental value and market value aren’t always the same thing.

A ring that isn’t worth a fortune on the resale market may still be irreplaceable to the person who inherited it.