About Moissanite

A different stone, not an imitation

Moissanite is silicon carbide. Diamond is carbon. They are two separate gemstones that happen to be used in the same kind of jewellery, and each has its own properties. At Luriem we sell moissanite as moissanite. We never describe it as a diamond, on any page of this shop.

Where it comes from

In 1893 the French chemist Henri Moissan found tiny crystals in a meteorite crater in Arizona. He first took them for diamonds, and later identified them as silicon carbide. The mineral was named moissanite after him.

Natural moissanite is so rare that it is not practical to use in jewellery. Every moissanite gem you can buy today, including ours, is created in a laboratory. No mining is involved.

How it looks

More fire. Moissanite has a dispersion of 0.104, against 0.044 for diamond. Dispersion is how strongly a stone splits white light into colours, so moissanite throws more rainbow flashes, especially in sunlight. Some people love this; others prefer the whiter sparkle of a diamond. It is a matter of taste.

More brilliance. Its refractive index is 2.65 to 2.69, higher than diamond's 2.42, so it returns a lot of light to the eye.

Double refraction. Moissanite is doubly refractive. In larger stones, looking closely through certain facets, you may see the edges appear slightly doubled. At normal viewing distance this is not noticeable.

How it wears

Moissanite rates 9.25 on the Mohs hardness scale. Diamond is 10, and sapphire is 9. In practice that means it resists scratches in everyday wear and is suitable for a ring you wear every day.

The stone does not cloud or change colour over time. Like any gem it collects skin oils, soap and lotion, which dull the sparkle until it is cleaned: warm water, a little mild soap and a soft brush are all it needs.

A note on carats

Moissanite is about 9% lighter than diamond (3.22 g/cm³ against 3.52 g/cm³). A moissanite cut to the same size as a 2 carat diamond therefore weighs a little less. For this reason moissanite is commonly described by its diamond-equivalent size: the size a diamond of that carat weight would be.

Colour, clarity and the GRA report

Moissanite is graded for colour and clarity on the same letter scales used for diamonds, from D (colourless) downwards and from FL/IF (flawless) downwards. Our certified pieces arrive with a GRA report, which records the stone's measurements and grades.

To be clear about what it is: a GRA report describes a moissanite. It is not a GIA certificate, which is issued for diamonds.