Where to Buy Cabochons: Sizes, Shapes, and What to Look For Before You Buy

If you have ever searched for cabochons near you and come up with nothing, you are not alone. Cabs are one of those supplies that almost never turn up in a general craft store, and even dedicated bead shops tend to carry a thin selection. Most of us end up buying online eventually.

I have been sourcing stones since 1998, and I can tell you the hard part is not finding cabochons. It is finding ones that actually work for the piece you have in mind. Here is what I look at before I bring anything into the shop.

What a cabochon actually is

A cabochon is a stone shaped and polished with a smooth domed top and a flat back, with no faceting at all. The word comes from the French for little head. Cutters have worked this way for centuries because it is the best way to show off stones that get their beauty from color, pattern, or an optical effect rather than from sparkle.

That is why you almost always see labradorite, opal, moonstone, turquoise, and agate cut as cabs. Faceting would kill the flash on a labradorite. A dome brings it out.

Calibrated or freeform

This is the first real decision, and it depends entirely on how you work.

Calibrated cabochons are cut to standard sizes. 8x10mm, 10x14mm, 18x25mm, and so on. If you use ready made settings and bezel cups, you need calibrated stones. A 10x14mm oval drops into a 10x14mm setting and you are finished.

Freeform cabochons follow the stone instead of a template. The cutter works with whatever pattern the material offers, so you end up with shapes nobody else has. These are wonderful for wire wrapping, where you are building the setting around the stone anyway. They are much harder to use if you rely on commercial findings.

Most of the wire wrappers I know buy freeform. Most of the silversmiths buy calibrated. Neither is better. They just suit different processes.

Size, and why bigger is not always better

A 50mm cabochon photographs beautifully and then sits in a drawer for two years because it is too heavy to wear comfortably.

Rough guidance:

• 10 to 20mm works for earrings, rings, and small pendants
• 25 to 35mm is the standard pendant range and comfortable for daily wear
• 40mm and up is statement territory, and worth weighing before you commit

Weight matters more than dimensions. A 35mm agate and a 35mm hematite are very different objects hanging around someone's neck.

Grade, and what those letters really mean

You will see AAA, AA, and A on stone listings everywhere. There is no governing body behind those letters, so they mean whatever the seller decides they mean. Worth knowing before you pay a premium for one.

Here is what I look at instead:

• Polish. Run your thumb across the dome. It should feel like glass. Pitting, scratches, and dull patches will not improve with time.
• Symmetry. A wobbly oval will fight you the entire time you are wrapping it.
• The back. This is the one people forget. A flat, even back sits properly in a bezel. A rounded or uneven back rocks and never sets right.
• Undercutting. If the edge angles inward beneath the widest point, wire and bezels will slip straight off. Look at the profile, not just the face.

Buying online without regret

The obvious drawback is that you cannot hold the stone. A few habits make it manageable.

Look for listings with more than one photo, ideally from different angles. Optical stones like labradorite and moonstone have to be seen in motion to be understood, so a short video is even better. Check that dimensions are given in millimeters. Read whether the piece is one of a kind or one of a batch, because with natural material one of a kind usually means the stone in the photo is the stone that ships.

And buy from people who know their material. If a listing cannot tell you where a stone came from or how it was treated, that is usually information the seller does not have either.

Vintage cabochons worth watching for

Not every cab in my shop is stone. Some of my favorite pieces are vintage cabochons made of glass, Bakelite, or Lucite instead, and quite a few carry texture across the top rather than a plain smooth dome. They photograph differently from anything cut today, and they catch light in a way modern material rarely does.

These come out of the vintage Bead Hoard here at A Grain of Sand, and they are genuinely rare and unusual. Because they are old stock rather than something I can reorder, once a piece is gone, it is gone. I post them as Vintage Vault drops from time to time, so if glass, Bakelite, or Lucite cabs are your kind of thing, it is worth keeping an eye out for when those go up.

Where to start

We keep a rotating selection of cabochons here, both calibrated and one of a kind. Most of it is hand selected at gem shows, and every one of a kind piece is photographed individually so you know exactly which stone is coming to you.

Shop our cabochon collection

Browse gemstone beads and cabochons

If you are not sure what size you need for a project, write to us. We answer every message ourselves.