Opalescent glass art is also called moonstone glass by one maker: Anchor Hocking. It is one of the most enchanting materials ever crafted. With its milky glow, swirling colors, and gemstone-like shimmer, it’s no wonder collectors and designers still chase it today. Whether you’re new to the world of antique glass or a seasoned enthusiast, this guide will walk you through the history, artistry, and allure of opalescent glass, with a spotlight on one legendary maker: Kokomo Opalescent Glass Works .

What Is Opalescent Glass?

Opalescent glass is a type of decorative glass that mimics the soft, glowing quality of an opal. It’s typically translucent or semi-opaque, with milky streaks or swirls that catch and scatter light. The effect is created by adding chemicals—like bone ash or tin dioxide—to molten glass, then manipulating heat and cooling to produce that signature shimmer.

Unlike clear or colored glass, opalescent glass has depth. It glows from within, changing appearance depending on the light source and angle. That’s why it’s often called moonstone glass by one maker—it looks like it’s lit by moonlight. The maker Anchor Hocking calls their opalescent glass “Moonstone”.

Who Pioneered Opalescent Glass?

The golden age of opalescent glass began in the late 19th century, thanks to two American innovators: John La Farge and Louis Comfort Tiffany. Both artists were experimenting with stained glass for architectural windows and wanted richer, more painterly effects than traditional pot-metal glass could offer.

La Farge was the first to patent the process. In 1880, he received U.S. Patent No. 224,831 for a “Colored-Glass Window” using fused panes of opalescent glass. Tiffany followed closely, refining the technique and popularizing it through his iconic lamps and windows.

Early Uses: From Windows to Wonders

Opalescent glass was first used in stained glass windows. Unlike traditional glass, which relied on painted details, opalescent glass allowed artists to create depth and shading using the glass itself. This was revolutionary. Suddenly, windows could glow with layered color and texture, even without direct sunlight.

Tiffany’s studio used opalescent glass extensively in lamps, mosaics, and decorative panels, turning functional objects into fine art.

How Opalescent Glass Evolved in the 20th Century

In the early 1900s, opalescent glass moved beyond elite studios and into mass production. Companies like Fenton, Northwood, and Jobling began pressing opalescent glass into bowls, vases, and tableware. The Art Deco movement embraced it, especially in France, where Lalique and Sabino created ethereal sculptures and perfume bottles.

By mid-century, opalescent glass had become a staple in American homes. It was used in everything from carnival glass to kitchenware, often paired with iridescent finishes or bold colors.

Famous Makers of Opalescent Glass

Several glass houses stand out in opalescent history:

• Kokomo Opalescent Glass Works (KOG) – Founded in 1888, KOG is the oldest manufacturer of opalescent glass in the U.S. and still operates today.
• Fenton Art Glass – Known for hobnail patterns and colorful opalescent carnival glass.
• Northwood Glass Company – Famous for pressed opalescent patterns like “Diamond Spearhead.”
• Lalique & Sabino (France) – Masters of Art Deco opalescent sculpture and tableware.
• Jobling (England) – Produced stunning opalescent bowls and vases in the 1930s.

Studio Artists and One-of-a-Kind Creations

While many pieces were factory-made, opalescent glass also thrived in studio settings. Artists like Dale Chihuly and Johnny Camp (Opal Art Glass) explored opalescent effects in blown glass forms. These pieces are often more abstract, with layered colors and organic shapes.

Studio opalescent glass tends to be more experimental, blending traditional recipes with modern techniques.

Most Sought-After Opalescent Pieces

Collectors love:

• Tiffany lamps with opalescent panels
• Fenton’s Persian Pearl punch bowls
• Northwood’s blue opalescent vases
• Sabino’s animal figurines and Art Deco sculptures
• Kokomo’s early sheet glass used in historic buildings

Rare pieces with complex patterns, deep color contrast, or documented provenance can fetch thousands at auction.

Popular Colors and Patterns

Opalescent glass comes in a dreamy palette:

• Blue opalescent – Often called “sapphire” or “aqua”
• Vaseline opalescent – Yellow-green glow, fluoresces under UV light
• Peach opal – Soft pink-orange blend
• White moonstone, (Anchor Hocking) – Classic milky translucence
• Swirled multicolor – Especially in French Art Deco pieces

Patterns range from hobnail, ruffled edges, and pressed florals to abstract swirls and figural motifs.

Is Opalescent Glass Still Made Today?

Yes! Kokomo Opalescent Glass still produces hand-mixed sheet glass using original 19th-century recipes. Other companies like Paul Wissmach Glass Co. also offer opalescent styles for stained glass artists and restorers.

Modern studio artists continue to explore opalescent effects in blown and fused glass.

Opalescent vs. Milk Glass: What’s the Difference?

Though they look similar, they’re quite different:

• Milk glass is opaque and solid-colored, usually white. It’s made by adding opacifiers like bone ash.
• Opalescent glass is translucent, with glowing edges and streaks. It reacts to light and often has layered colors.

Milk glass is more uniform; opalescent glass is dynamic and light-sensitive.

Oldest Signature Piece

The oldest documented opalescent glass piece is likely John La Farge’s 1879 stained glass window, exhibited just before his patent was filed. Kokomo’s earliest sheets, used by Tiffany in the 1880s, are also considered foundational.

Differences Between Makers

Each glass house had its own style:

• Tiffany emphasized painterly effects and layered shading.
• Kokomo focused on sheet glass for architectural use.
• Fenton leaned into pressed patterns and vibrant carnival finishes.
• Sabino and Lalique created sculptural forms with soft, glowing translucence.

The differences lie in technique, intended use, and artistic vision.

Final Thoughts: Why Collectors Love Opalescent Glass

Opalescent glass is more than beautiful—it’s magical. It captures light like a gemstone, tells stories through color, and bridges the gap between art and utility. Whether you’re drawn to the elegance of Tiffany or the charm of Fenton, there’s a piece of opalescent glass waiting to glow in your collection.

Sources: Glass Encyclopaedia BuffaloAH & JLSloan, [Patent History] Kokomo Opalescent Glass Works, Fenton Collectibles