3 Things You Should Know About Opaline Glass
Curio IQ Series: Let’s take a short and sweet lesson in antiques!

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Image via Architectural Digest

Image via Eddie Ross
If you’ve flipped through a design magazine or coffee table book in the last 30 years, then chances are you’ve spied a table or two set with brilliant aqua goblets in varying sizes but all with a timeless wafer stem. This bold color is always eye catching and instantly recognizable once you know it’s opaline glass!
Long treasured for its opalescent qualities, opaline glass whether in bright white, bold aqua, shell pink, or sunny yellow is enchanting. Goblets weren’t the only form made. You’ll also find it as trinket boxes, elaborate vases, and vanity bottles.
No. 1 What is Opaline Glass?
A type of colored glass that is semi-opaque and was made to resemble porcelain using bone ash as well as metal oxides for the color. When held up to light it shows its translucency and has a red or pinkish tint, and this gave opaline its nickname “fire glass.”

Imperial glass aqua opaline goblets
No. 2 Authentication Clues
Mid-19th century opaline was made by hand, using free-blowing techniques. The surface should be smooth with no seam marks from a mold although the separate pieces like the bowl and stem may have been blown separately then fused together. The bottom will often show a pontil mark where the piece was broken from the rod.
Take a look at this close up of the stem! See the seam line running down the middle?

Imperial Glass aqua opaline goblet with seam line circa 1960
Look for stickers! Imperial Glass (US 1960s) and Portieux Vallerysthal often have stickers on the bases.

Imperial Glass sticker on base of opaline glass goblet
No. 3 History
Two of the most sought after French opaline brands are Baccarat and Portieux Vallerysthal. Baccarat as the originator of opaline made some of the most exquisite and elaborate examples with delicate painted designs and ormolu mounts.
Portieux Vallerysthal is well known for their series of aqua drinking goblets produced in the 1930’s (those we discussed above). The company originally opened in the 1830s and was first known for their cameo glass.
For more on the history of opaline glass and how to authenticate it read The Grandmillennial’s Pocket Guide to Chic Antiques!
Shopping for opaline glass? Here are some good looking options from around the web:
A real opaline when close to light -lamp should show a… reddiness .,and that is probably why is called fire glass.
Hi Olga! Thanks for the clarification. Yes, it shows a red or pinkish tint when held up to light. I’ve re-worded that sentence for clarity.