Can a pearl be set in a ring?

It can, but it will not last. At 2.5–4.5 a pearl is softer than most things a hand touches. Moonstone is a far more practical June stone for a ring.

Birthstone jewellery: what to know first

Q: Which birthstone is toughest for an everyday ring?

April's diamond at 10 on the Mohs scale, followed by July's ruby and September's sapphire at 9. All three shrug off daily wear indefinitely.

Q: Does treatment make a stone worth less?

Disclosed treatment is normal, not a defect. Nearly all blue topaz is irradiated, most citrine is heated amethyst, and the majority of sapphire is heat-treated. Untreated stones carry a premium; treated ones are not fakes.

Which stones survive being worn on a hand every day, which quietly fall apart, and why the difference comes down to one number.

Birthstone durability by month
Month	Stone	Mohs	Suitable for
January	Garnet	6.5–7.5	Daily wear with care Fine for rings, but avoid knocks against stone and metal.
February	Amethyst	7	Daily wear with care Fine for rings, but avoid knocks against stone and metal.
March	Aquamarine	7.5–8	Daily wear with care Fine for rings, but avoid knocks against stone and metal.
April	Diamond	10	Daily wear, any setting Hard enough for a ring worn every day.
May	Emerald	7.5–8	Daily wear with care Fine for rings, but avoid knocks against stone and metal.
June	Pearl	2.5–4.5	Protected settings only Scratches easily. Keep it off the hands entirely.
June	Moonstone	6–6.5	Occasional wear Better in earrings or pendants than in a ring.
June	Alexandrite	8.5	Daily wear, any setting Hard enough for a ring worn every day.
July	Ruby	9	Daily wear, any setting Hard enough for a ring worn every day.
August	Peridot	6.5–7	Occasional wear Better in earrings or pendants than in a ring.
August	Spinel	8	Daily wear, any setting Hard enough for a ring worn every day.
September	Sapphire	9	Daily wear, any setting Hard enough for a ring worn every day.
October	Opal	5.5–6.5	Occasional wear Better in earrings or pendants than in a ring.
October	Tourmaline	7–7.5	Daily wear with care Fine for rings, but avoid knocks against stone and metal.
November	Topaz	8	Daily wear, any setting Hard enough for a ring worn every day.
November	Citrine	7	Daily wear with care Fine for rings, but avoid knocks against stone and metal.
December	Turquoise	5–6	Protected settings only Scratches easily. Keep it off the hands entirely.
December	Zircon	6–7.5	Occasional wear Better in earrings or pendants than in a ring.
December	Tanzanite	6–7	Occasional wear Better in earrings or pendants than in a ring.

Why hardness decides everything

Ordinary household dust contains quartz, which sits at 7 on the Mohs scale. Anything softer than 7 is therefore being sanded, very slowly, by the air in your house. That is the entire reason an opal ring goes cloudy after a few years while a sapphire ring does not.

Rings take the most punishment — hands hit doorframes, desks and keyboards all day. Earrings and pendants hang free and are hit by almost nothing. A stone that is a bad idea in a ring is often perfectly sensible in a necklace.

The months that need care

June — pearl (2.5–4.5). Softer than a copper coin. Dissolved by acid, so perfume, hairspray and sweat all attack it. Put it on last and wipe it after wearing.
October — opal (5.5–6.5). Contains up to 21 percent water and can craze — develop fine internal cracks — if it dries out or suffers a sudden temperature change. Never leave it in a hot car.
December — turquoise (5–6). Porous. Absorbs oils and changes colour over years of contact with skin. Some owners consider that a feature.

Settings

A bezel setting wraps metal fully around the stone and protects the edges — the sensible choice for anything under 7. Prongs show more of the stone and expose it more; fine for diamond, ruby and sapphire, risky for opal and pearl.

One more practical point: never store stones loose together in one box. Diamond at 10 will scratch every other stone you own, and it does not need much contact to do it.

Cleaning

Warm water, mild soap and a soft brush suit most stones at 7 and above. Ultrasonic cleaners are risky for anything porous, fractured or heat-treated — that rules out emerald, opal, turquoise, pearl and most tanzanite. Selenite is water-soluble and should never be rinsed at all.

Questions

Which birthstone is toughest for an everyday ring?

April's diamond at 10, followed by July's ruby and September's sapphire at 9. All three shrug off daily wear indefinitely.

Can I put a pearl in a ring?

You can, but it will not last. At 2.5–4.5 a pearl is softer than most things your hand touches. If you want June in a ring, moonstone or a lab-grown alexandrite is a far more practical choice.

Is a treated stone worth less?

Treatment is normal and disclosed treatment is not a defect — nearly all blue topaz is irradiated, most citrine is heated amethyst, and the majority of sapphire on the market is heat-treated. Untreated stones command a premium, but treated ones are not fakes.