The feldspar group contains a wide range of shimmering, colour-shifting gemstones, including moonstone, labradorite, and sunstone. These gems are prized for their unique optical effects—whether it's the ethereal glow of moonstone or the iridescent flash of labradorite. Though not as hard as other gemstones, their visual impact makes them treasured additions to antique and vintage jewellery collections.

What Are Feldspar Gemstones?

Feldspar is a family of minerals that includes several varieties used in jewellery. Among the most well-known are:

• Moonstone: Known for its soft, glowing adularescence, which appears as a floating light or sheen across the gem’s surface.
• Labradorite: Famous for labradorescence, a bold iridescent play-of-colour in blue, green, orange, or violet flashes.
• Sunstone: Displays a glittering, metallic aventurescence due to tiny reflective inclusions.

All three are most often cut en cabochon to showcase their optical properties, and they appear frequently in antique jewellery from the late 19th and early 20th centuries.

Gemstone Characteristics

• Hardness: 6–6.5 on the Mohs scale
• Toughness: Poor to fair
• Lustre: Vitreous to pearly
• Colour: Blue, peach, green, grey, iridescent
• Crystal System: Monoclinic (orthoclase) and Triclinic (plagioclase)

Common Cutting Styles

These gems are most commonly cut as smooth cabochons to maximise their optical effects. Fancy shapes like ovals, teardrops, and shield cuts are also used to suit the flowing, organic styles of Edwardian and Art Nouveau jewellery. Labradorite may also be faceted, though this is less common.

Use in Antique and Vintage Jewellery

Moonstone was especially popular in Art Nouveau designs, where its soft sheen complemented the movement's curving lines and naturalistic motifs. It also appears in late Victorian and Edwardian rings, sometimes paired with pearls or small diamonds. Sunstone and labradorite, while more niche, occasionally feature in Arts & Crafts or early 20th-century pieces—particularly when unusual colour and texture were desired.

Symbolism and Lore

Moonstone has long been associated with femininity, intuition, and lunar energy. In some cultures, it was believed to bring dreams and foresight. Labradorite is thought to be a stone of transformation and protection, while sunstone symbolises vitality and joy. All three were historically regarded as mystical or spiritual gems, making them especially appealing in esoteric or symbolic jewellery.

Are Feldspar Gems Suitable for Daily Wear?

Feldspar gemstones have moderate hardness but poor to fair toughness, which means they can chip or cleave if struck. They are best worn in settings that protect the stone, such as bezel settings, and are ideally suited to occasional rather than everyday wear. When storing, keep them separate from harder gemstones to avoid scratching.