Grey Moonstone

Grey Moonstone is a variety of feldspar moonstone with a smoky gray to silvery, semi-translucent body and a soft adularescent glow, frequently silvery blue. It is sometimes marketed as "new moon stone," complementing white moonstone's "full moon" associations.

The stone's appeal lies in the contrast between its misty gray base and the floating sheen that drifts across the surface as it is moved. The body can range from light, almost translucent gray to deeper smoky tones, with the best stones showing a clear blue glow.

Like all moonstones, its sheen, adularescence, comes from light interacting with microscopic internal feldspar layering rather than from any coloring agent.

Grey Moonstone forms as feldspar crystallizing in igneous rocks such as pegmatites and granites. As the crystal cools slowly, two feldspar phases unmix into alternating microscopic layers (exsolution lamellae), and light scattering from those layers produces the adularescent sheen.

The smoky gray body color results from fine inclusions and the optical character of the feldspar. Grey moonstone is sourced from localities including India, Sri Lanka, and Madagascar. The intensity and color of the glow depend on the fineness and orientation of the internal layering, and stones are cut as cabochons oriented to maximize the floating sheen.

Grey Moonstone is a feldspar of Mohs 6-6.5 with two cleavages near 90 degrees and a vitreous to pearly luster. It is recognized by a smoky gray to silvery translucent body with a soft, floating blue or silver adularescent glow that shifts as the stone tilts; streak is white.

The sheen is billowy and moves with the stone, unlike the spectral flash of labradorite. Some grey moonstone also shows faint multicolor or rainbow tints.

Distinguish it from grey chalcedony or grey agate (no adularescence, different luster, no feldspar cleavage) and from labradorite (broad spectral flash). Glass imitations lack the genuine internal billowy glow and feldspar cleavage.

Grey Moonstone is used as a gemstone, cut into cabochons, beads, and freeform shapes for rings, pendants, and earrings. Its moody gray body and silvery-blue sheen make it popular in contemporary and bohemian jewelry, and it is often paired with sterling silver.

Value depends on the strength and color of the adularescence and the clarity of the body. As a feldspar with cleavage, it benefits from protective settings and gentle handling.

In metaphysical traditions grey moonstone is associated with the new moon, intuition, mystery, and new beginnings; these are traditional beliefs rather than scientifically established properties.