Oval cabochon of rainbow moonstone (oligoclase, feldspar group), 19×14×7 mm. Translucent white base with multicolor adularescence — flashes of blue, violet, and gold — visible when moving the gem under light. Flat back. Unique piece selected at a wholesale lapidary market.
Piece Details
| Mineral |
Rainbow Moonstone (oligoclase, feldspar group) |
| Dimensions |
19×14×7 mm. Variation of ±0.5 mm in any dimension. |
| Shape and Back |
Oval, flat back |
| Finish |
Mirror polish |
| Hardness |
6–6.5 Mohs — we recommend a closed bezel setting to protect the gem's edge |
| Origin |
India (world's main source of gem-quality rainbow moonstone) |
| Treatment |
No treatment |
| Type of Piece |
Unique piece |
About This Specific Piece
The adularescence of this rainbow moonstone is multicolored: under direct illumination, flashes of blue, violet, and gold appear, changing position as the gem is rotated. The effect is more intense when the cabochon is moved — the light seems to shift from within, not reflect off the surface. This is the usual optical behavior of high-quality oligoclase with well-developed exsolution layers.
The 19×14 mm format is a statement size: large enough for the adularescence effect to be visible and impressive to the naked eye, without reaching the volume of a collector's piece. The 7 mm flat back allows for a standard medium-depth bezel setting. The oval shape facilitates mounting without custom fabrication.
How Adularescence Forms
Rainbow moonstone has an internal structure of alternating layers of feldspars with slightly different compositions (oligoclase and albite), formed during the slow cooling of igneous rock by a process called exsolution.
Suitable Mounting Applications
-
Bezel setting (925 silver) — recommended. The 6–6.5 Mohs hardness makes the edge susceptible to impacts; the bezel provides perimeter protection.
-
Statement ring — the 19×14 mm has enough presence for a ring's central piece; the jeweler builds the bezel adapting it to this specific piece.
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Wire wrap — the mirror-polished surface facilitates wrap positioning without marking the gem; the wire wraps around the perimeter, leaving the top face free.
Moonstone in Lapidary Tradition
The name "moonstone" has historically been applied to various feldspars with adularescence.
In India, moonstone holds deep cultural significance. It is considered inauspicious to buy or sell it on days other than Monday (the day of the moon); traditional vendors in Jaipur markets still observe this ritual today. In Hindu tradition, moonstone is a sacred stone linked to the lunar goddess and is given as a symbol of good fortune for second marriages.
In crystal tradition, rainbow moonstone is associated with natural cycles and intuition. 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
Genuine adularescence floats inside the stone — not on the surface — and changes position when the gem is moved, not just when the eye's angle changes. Iridescent glass imitations have the effect on the surface and do not move with orientation. Under 10× magnification, natural moonstone shows a pattern of internal layers (sometimes called "fly's eye" in gemology) that is a structure, not a treatment.
Frequently Asked Questions
Is the adularescence real in this piece?
Yes. The multicolor adularescence is a structural optical property of this oligoclase, not a treatment or coating. The effect is produced by light diffraction between internal layers of the mineral and is permanent.
Has the stone undergone any treatment?
No treatment. Rainbow moonstone does not require any process to achieve adularescence — it is an intrinsic property of the mineral.
See also: cabochon collection · silversmithing · wire wrap.
