What Is a Locket Necklace and How Does It Work? | Hidden Keepsake Space

A locket necklace is a pendant with a compartment that opens to hold a tiny keepsake — usually a photo — and closes to protect it.

A locket looks like any other pendant until you find the seam. Run a thumbnail along the edge and the front swings open like a tiny book, revealing a shallow cavity sized for one small, flat object. That hidden space is the point — and where the practical questions live: how the piece opens, what fits inside, and how to avoid bending the frame on the first try.

What Can You Actually Put Inside a Locket?

Most lockets are built around a photograph, but the compartment is really a small flat-memento holder. Anything thin enough to sit inside without forcing the closure will work.

• Photographs — a portrait trimmed to the interior shape.
• Handwritten notes — a short message folded flat.
• Dried flowers — pressed flat first, since fresh petals add moisture.
• A lock of hair — a traditional Victorian use still seen in modern memorial lockets.
• Other small flat mementos — a stamp, a fabric swatch, a printed phrase.

Many designs are double-sided, holding one item per face, so a photo can sit opposite a note. Blue Nile’s locket listings describe small frames and clear plastic film that hold a photo flat and shield it from contact. Use that film if included — it keeps the image from shifting every time the piece opens.

Size is the real constraint. A locket interior is measured in millimeters, so anything thicker than the cavity depth keeps the lid from sitting flush. If a keepsake does not fit without pressure, it is the wrong keepsake.

How Does a Locket Open and Close?

A locket opens when you release its specific closure — a notch, tab, groove, clasp, or slide — and the two halves separate. Knowing yours before you pry keeps the frame straight. Common types:

• Hinged and spring-hinge — one side pivots open; start at the small notch or tab near the edge.
• Friction-fit — the front is held by tension alone, so a gentle thumbnail lift at the seam releases it.
• Slide and push — the face shifts sideways or presses inward rather than swinging out.
• Magnetic — two halves snap apart with light pull and snap back together.
• Screw-top — the face unscrews, common on round and cylindrical shapes.

Once open, set the item into the cavity, close the piece, and confirm the halves sit even with no gap. A lid that will not close flush almost always means the contents are too thick.

On current hinged designs sold by Blue Nile and Kay, the seam runs along one edge with the hinge directly opposite. On older or friction-fit pieces, look for a tiny notch cut into the rim — that groove is the intended release point.

What Do Lockets Look Like, and Which Shape Holds What?

The classic shapes are oval, round, heart, and rectangle, and the shape decides how much you can store and how a photo crops.

The pendant hangs from a chain like any other necklace, so the visible design carries the style while the cavity stays hidden against the chest. When comparing pieces, interior dimensions matter more than outer size — a large decorative locket can still hold a very small photo. Our guide to the best locket necklaces breaks that down by piece.

Care Rules That Prevent the Two Most Common Mistakes

Lockets get damaged in the same two ways almost every time, and both are avoidable.

The first is forcing a spring locket with a knife, screwdriver, or other metal tool. That bends the frame and can leave a lid that never closes flush again. Use a fingernail, a plastic opener, or the notch the maker provided.

The second is moisture. Enclosed photos and fabric linings trap damp air against the contents, so Vogue’s locket coverage advises against soaking the piece and against wearing it into a shower, pool, or bath. Open the locket over a soft surface such as a towel — if the frame or a photo slips, it lands somewhere forgiving instead of on tile.

Keep the interior dry, open it gently and only when needed, and confirm the closure seats evenly each time. A locket that closes flush with no gap is doing its job.