Natural Moonstone · 2.203 ct · Marquise Cabochon · Light Greenish Blue Adularescence

This individually documented natural Moonstone weighs 2.203 carats and has been fashioned into an elegant marquise-shaped cabochon, polished on both sides. The gemstone displays an unusual combination of clear and milky white areas, accompanied by a delicate light greenish-blue adularescence that shifts across the stone as the viewing angle and illumination change.

Measuring approximately 12.0 × 5.9 × 4.0 mm, the elongated marquise outline gives the gemstone a refined and distinctive presentation. The smooth cabochon form is particularly appropriate for Moonstone because it allows the characteristic adularescent sheen to move visibly across the surface rather than relying on conventional facet brilliance.

The gemstone is recorded as transparent, although the natural contrast between its clearer and milkier areas creates visible variation in transparency throughout the stone. This internal variation contributes to its individual appearance and provides a changing background for the light greenish-blue sheen.

Light Greenish-Blue Adularescence

Adularescence is the characteristic optical phenomenon associated with Moonstone. It results from the interaction of light with extremely fine alternating feldspar layers within the gemstone. These microscopic lamellar structures interfere with and scatter incoming light, creating the characteristic floating or cloud-like sheen visible beneath the surface.

In this specimen, the effect presents as a light greenish-blue adularescence, producing a softer and slightly greener expression than the more familiar pure blue sheen. The strength and position of the effect change naturally as the stone is tilted or viewed from different directions.

The cabochon has been polished on both sides, allowing the internal structure, variation in transparency and adularescent effect to be appreciated from multiple viewing angles.

No indications of heating or other treatments have been recorded for this gemstone. It is therefore presented in its naturally documented state, with its colour, internal structure and optical phenomenon preserved as recorded.

The overall cutting quality ranges from Fair to Good, with Fair to Good symmetry and polish and a Good lustre. These characteristics support a pleasing overall presentation while retaining the individual natural character of the material.

Moonstone belongs to the feldspar group and has a hardness of approximately 6 on the Mohs scale. Its layered internal structure is responsible for the adularescent phenomenon that distinguishes Moonstone from many other transparent to translucent gemstones.

As a natural gemstone, internal inclusions, lamellar growth structures, fine fissures, subtle internal variations and minor surface-reaching features may occur. These characteristics form part of the geological development of the material and can influence the distribution and visibility of the adularescent sheen.

With its distinctive marquise form, contrasting clear and milky internal appearance and delicate light greenish-blue adularescence, this 2.203 ct natural Moonstone offers an individual expression of feldspar’s characteristic optical behaviour. Its double-sided polish and untreated status further enhance its appeal for collectors, bespoke jewellery or unique gemstone designs.