Micro round rainbow moonstone cabochons, 4 mm in diameter, with a flat back. The blue flash of adularescence — visible even in 4 mm pieces under spotlight — makes these cabochons a refined choice for pavé, ring accents, or 925 silver stud earrings. Available in lots of 4 or 12 pieces. Selected from a wholesale lapidary market.
Item Specifications
| Mineral |
Rainbow Moonstone (oligoclase, sodium-calcium feldspar; commercially "rainbow moonstone") |
| Dimensions |
Approximately 4 mm in diameter. Variation of ±0.5 mm due to hand-cutting. |
| Shape and Back |
Round, flat back |
| Finish |
Mirror polish |
| Hardness |
6–6.5 Mohs — we recommend bezel setting for protection in daily wear |
| Origin |
India (Rajasthan) |
| Treatment |
Untreated. The blue flash is natural (adularescence from feldspar layer interference) |
| Item Type |
Available in lots of 4 pieces or 12 pieces |
About this specific item
At 4 mm in diameter, each moonstone is the equivalent of a small point of light on the skin. The blue flash is visible under LED spotlight or direct sunlight, and disappears with diffuse light — this behavior is what defines authentic adularescence and distinguishes moonstone from white glass or milky quartz.
The lot may contain pieces with flashes ranging from sky blue to milky blue-white, depending on the cutting orientation relative to the feldspar planes in each crystal. This variation is inherent to the material and part of its natural character.
How adularescence forms
Moonstone (adularia or oligoclase) is composed of alternating layers of two varieties of feldspar with slightly different refractive indices, formed during the slow cooling of magma. When light penetrates the stone, it reflects and refracts at the interfaces between these layers — a process called internal interference.
For which setting it works
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925 Silver Pavé — at 4 mm, these cabochons are the ideal size for pavé of round cabochons around a larger central stone.
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Stud Earrings — a single 4 mm cabochon in a minimalist stud earring is discreet and versatile for daily wear.
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Ring Accents — as a side accent flanking a central stone, 4 mm balances without competing with the main piece.
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Detail Wire Wrap — in wire wrap, 4 mm is used as an accent in branched or floral designs.
Moonstone in history
In India, moonstone has been considered sacred for centuries; it was displayed on black silk fabrics to enhance the floating blue light.
In crystal tradition, moonstone is associated with intuition, natural cycles, and lunar energy — especially in its rainbow variety, which adds the dynamism of multicolored adularescence to lunar serenity.
The symbolic properties attributed to minerals belong to cultural and historical traditions. They are shared for educational purposes, not as medical advice or a substitute for professional care.
How to recognize genuine rainbow moonstone
Authentic adularescence has a point of maximum luminosity that moves when the stone is tilted; white glass or milky quartz show uniform luster without a moving point. Genuine moonstone is slightly heavier than glass of the same dimension (density ≈2.57 g/cm³) and cooler to the first touch.
Frequently Asked Questions
Is the blue flash visible in a stone only 4 mm?
Yes, under pinpoint light (LED spotlight, sunlight) adularescence is visible even at 4 mm. Under diffuse or fluorescent light, the stone appears milky white with no appreciable flash. This behavior is exactly as expected and is a sign of authenticity.
Do all pieces in the lot have the same flash?
Not exactly. Adularescence depends on the orientation of the feldspar planes in each crystal, which varies from piece to piece even in material from the same lot. Some will show intense sky blue; others, a softer blue-white glow. This variation is natural and adds diversity to the design.
More about rainbow moonstone: properties, history and meaning. See also: all our cabochons · handmade earrings.
