Moonstone, Labradorite & Iolite Necklace

None of these three stones look the same twice.

Stand still and you would never find that out.

What this necklace is

This necklace sets three stones side by side as a fixed cluster on a fine cable chain of 18ct gold-plated 925 sterling silver: a 4x6mm pear-shaped moonstone cabochon in the centre, a 3x5mm pear-shaped labradorite cabochon tilted against it on one side, and a 2mm round faceted iolite on the other. All three sit in irregular, hand-formed bezels with visible molten edges rather than neat machined rims. The chain measures 40cm with a 5cm extender, giving an adjustable 40 to 45cm length. House Of The 18th supplies this necklace as a single piece.

What is moonstone?

Moonstone is a feldspar, made of alternating microscopic layers of orthoclase and albite. Light entering the stone scatters between those layers and comes back as a floating blue-white glow that moves as the stone moves. That effect is called adularescence, and it is the reason moonstone is always cut as a smooth cabochon rather than faceted — facets would break up the very effect people buy the stone for. Moonstone rates 6 to 6.5 on the Mohs scale.

What is labradorite?

Labradorite is also a feldspar, and its flashes of blue, green and gold come from light interference across microscopic twinning planes inside the crystal. That effect is called labradorescence, and like adularescence it only appears at certain angles. A labradorite lying flat on a table can look like a plain grey stone; the same stone on a moving collarbone does not. Labradorite rates 6 to 6.5 on the Mohs scale.

What is iolite?

Iolite is the gem-quality form of the mineral cordierite, and it rates 7 to 7.5 on the Mohs scale. Its defining property is strong pleochroism: the same iolite crystal shows violet-blue from one direction, pale grey-blue from another and yellowish-grey from a third. Vikings are widely reported to have used thin slices of iolite as a polarising filter to locate the sun through cloud, which is why iolite is sometimes sold as the water sapphire or the Viking compass stone.

Why all three stones need you to move

Most jewellery is designed to look its best in a photograph. This necklace is not. Moonstone needs movement for its adularescence, labradorite needs movement for its labradorescence, and iolite changes colour with viewing angle. House Of The 18th put the three together precisely because the piece is worth more on a person than it is on a shelf — and because a stone that only performs when you are wearing it is a stone that rewards being worn rather than stored.

How the 40+5cm length wears

At 40cm the necklace sits at the base of the throat, just above the collarbone, where the stone cluster is fully visible against skin above any neckline. At the full 45cm it drops to sit on the collarbone itself and works over a crew neck or a shirt collar. Because the cluster is fixed on the chain rather than hanging from a bail, it stays centred and does not slide, which also makes it easy to layer with a longer pendant chain beneath it.

How to care for feldspar stones

Moonstone and labradorite are both feldspars at Mohs 6 to 6.5 and both have distinct cleavage, meaning they can chip or split on a sharp knock more readily than their hardness alone suggests. Never use an ultrasonic or steam cleaner on either. Take the necklace off before showering, swimming or sleeping, keep it away from perfume and hairspray, wipe it with a soft dry cloth after wearing, and store it flat so the chain does not tangle and the cabochons do not knock against harder pieces.

Specifications

Frequently Asked Questions

What causes the blue glow in moonstone? The blue glow in moonstone is called adularescence and is caused by light scattering between microscopic alternating layers of orthoclase and albite feldspar inside the stone, not by any dye or coating.

Are the moonstone and labradorite treated? Moonstone and labradorite are both used untreated in this necklace; their optical effects are structural properties of the crystal and cannot be added by treatment.

What does 18ct gold-plated mean? 18ct gold-plated means a thin layer of 18-carat gold is applied over a 925 sterling silver base, and the "18ct" describes the purity of the gold in the plating, not the thickness of the plating and not any carat weight of the stones.

How long is the chain and can it be adjusted? The chain is 40cm with a 5cm extender, so it can be worn anywhere between 40cm at the base of the throat and 45cm on the collarbone.

How durable is this necklace for daily wear? Moonstone and labradorite rate 6 to 6.5 on the Mohs scale and both have cleavage that makes them chip-prone on a knock, so this necklace suits regular wear but should be removed for sport, swimming and sleeping.