How to Choose a Gemstone: What Should You Look For?

October 1, 2026

Choosing a gemstone can feel a little overwhelming.

There are colours, cuts, sizes, clarity, treatments, origins and all sorts of terminology to consider. It is easy to wonder whether there is a particular formula for finding the “right” gemstone.

But we don't think there is.

A gemstone can be technically impressive and still not be the stone for you. Another may have characteristics that aren't considered ideal on paper, yet something about its colour, personality or the way it catches the light keeps drawing you back.

At the end of the day, choosing a gemstone is both about understanding what you're looking at — and discovering what makes you stop and look twice.

Start With Colour

For many people, colour is the first thing that catches the eye.

When looking at a coloured gemstone, you might consider its hue, tone and saturation.

Hue is the colour itself — perhaps green, pink, blue or something in between.

Tone describes how light or dark the colour appears.

Saturation describes how intense or vivid that colour is.

But these are not simply measurements of whether a gemstone is beautiful.

A vivid, highly saturated gemstone may be exactly what one person is looking for, while someone else may prefer a softer pastel or a more muted colour.

Even within the same gemstone variety, small differences in hue can completely change its personality.

This is one of the reasons we love coloured gemstones. There isn't necessarily one colour that a gemstone is supposed to be.

Look at the Cut

The cut is about much more than the shape of a gemstone.

Faceting, proportions, symmetry and the way the stone has been cut all influence how it interacts with light.

A well-cut gemstone can return light beautifully, creating brightness, sparkle and movement as the stone changes position.

But a gemstone does not need to be perfectly symmetrical or conventionally cut to be interesting.

Sometimes an unusual proportion, an unexpected shape or a particular cutting style is exactly what gives a stone its character.

What matters is how the cut works with that particular gemstone.

Don't Be Afraid of Inclusions

A light blue rectangular faceted aquamarine resting on a textured brown suede surface.

Inclusions are often treated as something to avoid, particularly when discussing gemstones in terms of clarity.

But natural gemstones are not manufactured objects. Their internal features are part of their story.

Some inclusions may affect transparency or durability and can be important considerations when choosing a stone. Others can contribute to a soft, velvety appearance or create interesting visual texture.

Featuring a 3.50ct natural purplish pink rhodolite garnet.

A gemstone doesn't always need to be perfectly clean to be beautiful.

In fact, sometimes the little things that make a stone less than perfect on paper are exactly what make it memorable.

Consider the Size

It is easy to assume that a larger gemstone must automatically be more impressive.

But size is only one part of the picture.

A smaller gemstone with beautiful colour and excellent light performance can be far more captivating to you than a much larger stone with a different colour or cutting style.

When choosing a gemstone, think about how the size, colour, cut and overall character work together, rather than considering carat weight on its own.

And remember that carat is a measurement of weight, not a direct measurement of size. Different gemstones have different densities, so two stones of the same carat weight can look quite different in size.

What About Treatments?

Treatments are an important part of the gemstone world, but they are not equally relevant to every gemstone.

Some gemstones are routinely discussed in terms of treatment. For example, heat treatment is a common consideration when buying ruby and sapphire, while other gemstones have their own treatment practices and considerations. GIA notes that coloured gemstones may be examined for treatments including heating, irradiation, fracture filling or clarity enhancement, coating, dyeing and diffusion.

This doesn't mean that every gemstone you encounter will have a treatment that needs to be identified or routinely discussed. The treatments that are common, commercially relevant and detectable vary considerably between gemstone types.

Treatment itself also doesn't automatically make a gemstone better or worse.

What matters is understanding what has been done to the stone, whether the treatment is stable, whether it affects the care requirements and whether relevant treatment information has been disclosed.

A pair of gold stud earrings with oval-cut blue sapphire and red vanadium spinel, displayed on a soft, light gray fabric surface.

Carter Mismatch Studs - featuring a 0.4ct heated sapphire.

Some treatments can also be difficult to detect. Gemological laboratories use specialised equipment and expertise to identify detectable treatments, but not every treatment can necessarily be identified with certainty in every stone. Treatment detection is an ongoing area of gemological research.

So if treatment information matters to you, particularly when purchasing a gemstone where treatment is an important value or care consideration, it is worth asking questions and obtaining a laboratory report where appropriate.

What About Origin?

You may also come across gemstones described by their geographical origin.

For certain gemstones, origin can be an important part of their story and may influence rarity, value or desirability. But there is an important distinction between where a gemstone was mined, where it was cut or treated, and where it was purchased or traded.

A gemstone purchased in Sri Lanka, for example, does not necessarily mean that the gemstone was mined in Sri Lanka. Gemstones can travel through different countries during their journey from rough material to finished stone, and may be cut, treated or traded far from their original geological source.

A Merelani mint garnet from Tanzania was actually faceted and sourced from Thailand.

This is why the country where a gemstone was purchased or cut should not, by itself, be taken as proof of its geological origin.

For some gemstones, laboratories can provide a geographic origin opinion based on characteristics such as inclusions, chemistry and spectroscopy. But origin determination is not always possible.

GIA describes geographic origin as an expert opinion, rather than an indisputable fact. Different deposits can produce very similar material, and even deposits within the same country can differ considerably. When the available evidence overlaps too much to reach a conclusion, a laboratory may report the origin as “inconclusive.”

Because origin reports are expert opinions, different laboratories can sometimes reach different conclusions about the same gemstone, particularly when the determination is difficult.

This doesn't make laboratory reports unhelpful. Quite the opposite — they can provide valuable information and, where an origin opinion can be established, an additional piece of the gemstone's story.

But origin is best understood as one part of the picture, rather than the entire story of a gemstone.

Look Beyond the Certificate

A laboratory report can tell you a great deal about a gemstone.

Depending on the report and the type of gemstone, it may identify the material, state whether it is natural or laboratory-grown, disclose detectable treatments and, for certain gemstones, provide an opinion on geographic origin.

These details can be extremely useful.

But a certificate cannot tell you whether you are going to love the stone.

It cannot measure the particular glow that catches your eye, the colour that you keep thinking about, or the way a gemstone comes alive when it moves in the light.

Specifications help us understand a gemstone, but they don't replace looking at the gemstone itself.

So, What Makes a Gemstone Worth Choosing?

This is where things become personal.

There isn't a checklist that can tell you which gemstone is the right one.

Colour, cut, clarity, size, treatment and origin can all tell us something about a gemstone. But none of them can tell you whether you will fall in love with it.

Maybe it is an extraordinary colour.

Maybe it is the way the stone comes alive when it catches the sun.

Maybe there is an unusual inclusion that gives it a soft, velvety appearance.

Maybe the cutting isn't quite what you expected, but somehow it makes the stone more interesting.

Or perhaps you simply keep looking at it.

We think that feeling matters.

How We Choose at Atelier Cara

When we select gemstones for Atelier Cara, we don't follow a single formula.

We look at the colour first, but we also consider how the stone interacts with light, how it has been cut, its proportions, clarity, inclusions and overall character.

Most importantly, we ask ourselves a very simple question: Does this stone make us stop and look?

Two gold pendant necklaces with cushion-cut pink gemstones, one resting on a textured gray stone and the other on a dark wooden surface.

We love how these two Juno pendants, though both feature a garnet, yet they look completely different and give a very unique vibe and character.

Sometimes the answer is found in an unusual colour. Sometimes it is an exceptional cut. Sometimes it is something much harder to describe — a certain glow, movement or personality that a gemstone seems to have all on its own.

We naturally gravitate towards stones with colour, life and character. But that doesn't mean there is one universal definition of beauty.

A gemstone that speaks to one person may not speak to another.

And that's exactly how it should be.

Choosing Your Own Gemstone

If you're choosing a gemstone for yourself, take your time.

Look at it from different angles. If possible, see it under different lighting. Pay attention to what catches your eye first, and then look a little closer.