What Is Moonstone, Really? A Plain-English Guide to the June Birthstone

Moonstone is one of those gems that everybody recognises and almost nobody can explain. It is not a diamond, it does not sparkle, and yet it holds the eye longer than most stones that do.

Here is what it actually is, in plain language, so you know what you are buying.

The geology, briefly

Moonstone belongs to the feldspar family, which is the most common mineral group in the earth's crust. What makes moonstone different is how it formed: two kinds of feldspar, orthoclase and albite, cooled together and separated into layers so thin you could not see them with a hand lens.

When light enters the stone it hits those layers and scatters, then floats back out as a soft sheen that seems to sit just under the surface and move as you move. Gemmologists call it adularescence, after Mount Adular in Switzerland where fine specimens were once found.

The important part for a buyer: that glow is entirely natural and structural. It is not a coating, not a treatment, and it cannot be added to a stone that does not have it.

Where it comes from

The classic sources are Sri Lanka and southern India. Sri Lankan material has long been considered the finest for blue sheen. Moonstone is also mined in Madagascar, Myanmar, Tanzania and the United States.

Australia has its own strong claim in the gem world, though it is opal rather than moonstone, which is why the two are so often shown together in local jewellery. If you like the milky glow of moonstone, you will very likely like moonstone and opal together.

Rainbow moonstone versus white moonstone

This confuses almost everyone, so let us be clear.

White moonstone is the classic: milky body, soft white to pale silver sheen, gentle and understated.

Rainbow moonstone is more transparent with a strong blue flash and often small internal fractures that catch other colours. Technically it is usually labradorite rather than orthoclase feldspar, which is a distinction gemmologists care about and no one else does.

Neither is fake and neither is superior. Rainbow reads dramatic, white reads quiet. Buy whichever you would rather look at on your own hand.

How to judge quality

• The sheen should move. Tilt the stone. The glow should drift across it. A stone that looks flat and grey from every angle is a poor one.
• Look for blue, not white, if you want the premium look. A clean blue sheen on a near colourless body is the classic top grade.
• Body should be clear-ish, not chalky. Very cloudy stones are common and cheap.
• Check the cut. Moonstone is almost always cut as a cabochon, a smooth dome. The dome should be centred so the sheen sits in the middle, not sliding off one side.

Living with moonstone: the honest care guide

Moonstone is about 6 to 6.5 on the Mohs hardness scale. Quartz, which is what most household dust is made of, is 7. That means moonstone can be scratched by ordinary dust if you rub it, and it has good cleavage, which means a sharp knock can split it.

In practice:

• Take rings off for gardening, cleaning and the gym. This is the single biggest thing.
• Clean with warm water, mild soap and a soft cloth. Never an ultrasonic cleaner.
• Store it separately from harder stones so nothing scratches it in the box.
• Keep it away from perfume and hairspray, which dull the surface over time.

None of this makes moonstone delicate to the point of being impractical. It simply means it is a stone for wearing, not for wearing while you scrub the oven.

The June birthstone

June has three official birthstones: pearl, alexandrite and moonstone. Moonstone is the one most people choose now, partly because good pearls are expensive and alexandrite is rare enough to be out of reach for most budgets.

It makes a lovely gift for a June birthday, and the Moonstone Necklace Floating Sway is our most given piece for exactly that reason.

Its long association with rest and intuition

Roman writers connected moonstone to moonlight itself. In India it has been considered a sacred stone for centuries, associated with the moon, with dreams and with the feminine. Travellers once wore it for safe passage at night.

Whether you take that literally or simply enjoy the history, the association is genuinely old and it explains why moonstone keeps turning up in the hands of people who want a calmer evening.

Where to start

For everyday: the Moonstone Ring Harlow. For a gift: the floating pendant above. For something with a little more presence: the Moonstone Ring Goddess.

Or see the full range in Gemstones.

Moon Vibe jewellery is made to be worn and enjoyed. Gemstones are not medicine, and nothing in this article is medical advice, diagnosis or treatment.