How to identify a real sapphire

Bonnot Paris

April 29, 2026

5 min read

The sapphire is a treasure for jewellery lovers, and because imitations exist, we are going to look at how to recognise a sapphire — from the least reliable methods to the most dependable. We will also cover quality assessment.

How to recognise a real sapphire?

A real sapphire can be confused with a synthetic sapphire. A blue sapphire can resemble other stones. The sapphire is a very popular stone, particularly in engagement rings.

A gemmologist can sometimes identify an authentic sapphire from a blue spinel or a tanzanite, but to the naked eye the distinction can be confusing. A more in-depth assessment is often necessary. Tanzanite and blue spinel are reminiscent of sapphire, but their compositions are very different.

The sapphire exists in a variety of colours, which are equally prone to confusion with other stones. It can be particularly difficult, for instance, to distinguish a pink sapphire from a pink spinel, as both display similar clarity and brilliance.

Sometimes, a real sapphire can be told apart from a synthetic sapphire by the presence of slight imperfections, whereas a fake sapphire has none. Laboratory-grown sapphires are created to be flawless. That said, some natural sapphires also have no imperfections visible to the naked eye.

The most reliable way to recognise a sapphire is to request a precious stone assessment from a professional and to obtain a certificate of authenticity, should it prove to be a genuine gemstone.

How to recognise a synthetic sapphire?

Synthetic sapphires are plentiful, though watchmaking professionals make use of them. The methods for identifying a synthetic sapphire are generally unreliable. This is the case with the breath test. You can, however, breathe onto a stone. The condensation might disappear slowly, which tends to indicate a fake sapphire.

Another (hit-or-miss) method: you could turn off the lights and use a small torch. The light emitted by certain synthetic sapphires can appear suspicious.

Finally, genuine high-quality sapphires contain no air bubbles, whereas fakes may — though not always, or not in a way that is visible to the naked eye…

Bear in mind that nothing compares to a microscope and spectroscopy. Maison Bonnot offers its gemmologist services in Angers.

How to assess the quality of a sapphire?

A high-quality sapphire may be a heated sapphire, but not necessarily a treated one. Heating is a widespread traditional process that is considered standard practice, unlike treatments that alter the nature of stones. Furthermore, a fine sapphire has no inclusions visible to the naked eye — at least, the vast majority of the highest-quality sapphires used in jewellery. The purity or clarity of a sapphire depends greatly on its inclusions, and the most sought-after sapphires, such as the Ceylon sapphire, are particularly pure. Where inclusions are present, the stone remains transparent.

The colour of a quality sapphire is intense and even. Colours can vary according to the origin of the sapphires, though certain regions of the world produce sapphires of differing hues. Burmese royal-blue sapphire, for example, is highly prized, yet Burma produces sapphires of various kinds. Identifying a precious stone is no easy task, but this type of clue can sometimes prove very useful.

Also on our website: how to recognise a ruby.

How to recognise a blue sapphire?

Not all dark blue sapphires are the most expensive or the most coveted. However, sapphires that are too pale are not sought after in fine jewellery.
The price of a blue sapphire varies according to quality and carat weight. As with a diamond, quality is assessed using the 4Cs — carat, cut, clarity and colour — to determine a price. In most cases, a small blue sapphire of excellent quality costs more than a larger blue sapphire of lesser quality.
The best way to avoid being deceived: purchase a blue sapphire, or one of another colour, with a laboratory certificate from a trusted seller who will be able to provide you with all the crucial information!