Is a Moonstone Bracelet Worth It? What the Sheen Is Paying For

Moonstone is a feldspar. Its blue-white float, called adularescence, comes from light scattering off very thin alternating layers of two feldspars that separated as the crystal cooled. Thin layers give a blue sheen, thicker layers a white one. Much of what separates one moonstone from another comes back to that layering, how strongly it scatters and what colour it shows, together with how clean the stone around it is.

A bracelet holds around twenty beads of that material. Each bead was cut from its own piece of rough and drilled on its own axis, so each one shows the sheen from a slightly different angle as the wrist moves. That movement is the reason to wear moonstone as beads. The judgement is about the strand as one object: how much light it gives back, whether that light is the same colour along the row, and how clear the beads look between the flashes.

What are you paying for in a moonstone bracelet?

Four things: the colour and spread of the sheen, the transparency of the body, the size of the beads, and how well the beads match each other. A blue sheen over a near-colourless body is the top of the range for this material. A white or silvery sheen over a slightly milky body sits below it, and a sheen that shows only as a faint glow at the edge of the bead sits lower still. Blue is the scarcer colour, and it shows best over a body with few inclusions.

Bead size multiplies all of that. Big clean beads are rare. Clean moonstone rough with a strong sheen is scarcer in larger pieces, so the same grade is harder to find at 8 mm or 10 mm than at 6 mm. Two moonstone bracelets that look alike in a thumbnail can differ in price for this reason.

Matching is the fourth cost. A strand reads well when its beads share the same sheen colour and the same body clarity, so the row looks like one material. Crystal 4T™ reads both. Transparency is how clear each bead is and whether milky patches show at wearing distance, about 40 cm, with the unaided eye. Tone is the body colour, its evenness within each bead and its consistency along the strand. For moonstone the sheen is read under Texture, together with the polish, and the tier of the piece follows the lowest of its material readings.

Why does the sheen move from bead to bead on a strand?

Because the sheen has a direction. Each bead points its own way. The layers that scatter the light lie in one plane inside the crystal, and the float is brightest when light meets that plane at the right angle. A cutter shaping a single cabochon can turn the rough so the sheen sits centred on the dome. A round bead is a sphere drilled through its middle, and the layers inside each bead sit wherever the rough put them.

So on the wrist a few beads flash, the wrist turns, and a different few flash. At any one moment some beads show blue, some show a white glow, and some show their body colour. This is what natural moonstone beads do. It is also why two beads under the same lamp look different from each other, and why a bracelet in the hand never looks quite like its product photograph. A photograph fixes one light and one angle; the beads change with every degree of turn. The physics of the effect, and its cousins in other stones, are in the piece on sheen, adularescence and the Tyndall effect.

The way to judge a strand is to look at it whole, in your own light. Roll it slowly under a window or a desk lamp and watch three things: how much of the row lights up over one full turn, whether that light is the same colour from bead to bead, and whether the beads look clean between the flashes. The sheen along the row, the body colour and clean bodies are what Crystal 4T™ scores as Texture, Tone and Transparency, and they shape the price. Twenty beads rarely light at the same instant; a strand that gives an even blue-white glow as it turns is doing what fine moonstone does.

Moonstone or rainbow moonstone: which one is on the record?

They are two feldspars. Classic moonstone is an alkali feldspar made of fine orthoclase and albite layers, and its sheen runs blue to white. "Rainbow moonstone" is a trade name usually used for white to colourless labradorite, a different feldspar, whose flash spreads into blue and sometimes green, gold and violet. Both are natural, both are feldspar, both are strung as bracelets, and they look different on the wrist. One gives a soft float that travels across the bead. The other gives sharper, more colourful flashes over a body that often carries small dark inclusions.

Price follows the material more than the name. A clean labradorite strand with a strong blue flash can be valuable, and so can classic moonstone with a blue sheen over a clear body. What matters is knowing which one you are wearing. On a BE. Stone Origin Record the material is written under Crystal Type, so the BE. moonstone strand reads feldspar (moonstone), and labradorite would be named as labradorite. The full mineralogy of both is in the moonstone complete guide.

The glass row is the easy one. Glass has no layering. Natural moonstone beads usually vary from one to the next because each holds its own layering; manufactured glass tends to glow the same way on every bead because it has no layering. The two are set side by side in moonstone vs opalite.

What does the Stone Origin Record say about treatment?

Moonstone can come untreated or treated, so treatment has to be stated for each strand. The treatments that do turn up on beads are surface ones: a thin coating to add colour or shine, and dye that lodges in fractures. Both change how a bead looks, and neither lasts as well as the stone underneath. A coating wears through at the drill hole and on the high points of the bead first, and dye sits in cracks as darker lines.

On the Stone Origin Record, treatment status has its own line and is written as a fact. Under the Crystal 4T™ entry rules, dyed, coated, filled or irradiated material does not enter BE. at all, and heated material is accepted only when the heating is declared on the Record and on the product page. BE.'s moonstone is recorded as untreated, which means the sheen and the body colour are the stone's own. The Record also carries the lot reference, the four readings as words, the tier, and the source country.

Where do the price differences between moonstone bracelets come from?

Four places: the grade of the material, the bead size, the matching, and the making. Material grade is the sheen colour and body clarity described above. Size is the amount of clean rough it takes to cut a sphere of that diameter. Matching is the selection work of putting twenty beads of the same colour and clarity in one row. One lot of rough yields beads across a spread of quality, so a strand held at one even level draws on more rough than a mixed one. The making is the drilling, the polishing and the stringing: a clean, centred drill hole with no chipping, a polish bright enough to let the sheen out, and wire and a clasp that hold. Texture on the Record reads the polish and the drill holes under 10× magnification, and for moonstone the sheen as well.

Two strands can be compared on those four points without knowing anything else about them. Read the Transparency, Tone and Texture words on the Record, look at the bead diameter, roll the strand in your own light, and check the drill holes and polish up close. A strand with Strong or Exceptional readings, 8 mm beads and an even glow along the row costs more than a Standard strand of 6 mm beads, and each step of that difference is visible.

How does moonstone hold up to daily wear?

Moonstone is 6 to 6.5 on the Mohs scale, a little softer than quartz at 7. Take it off for the gym and for heavy work with the hands, keep it in its box between wears, and the polish stays bright for years.

Cleaning is warm water, mild soap and a soft cloth. No ultrasonic cleaner and no steam, since both can open cleavage planes. Between wears it goes back in its box, apart from harder stones. The full routine is in the care guide for crystal jewellery, and the hardness chart shows where moonstone sits beside quartz, garnet and the rest.

1. GIA: Moonstone, overview of the feldspar and its sheen
2. GIA: Moonstone quality factors, blue sheen, clarity and body colour
3. GIA: Moonstone care and cleaning, hardness 6 to 6.5 and cleavage
4. Geology.com: Moonstone, orthoclase and labradorite moonstone, adularescence
5. Wikipedia: Moonstone (gemstone), composition and the origin of the sheen
6. BE.: Crystal 4T™ and the Stone Origin Record, how Transparency, Tone, Texture and Treasure are read