Gemstones and Birthstones: Topaz Gets the Blues (Blue Topaz, that is)

At the front end of the 21st century, you’re to be forgiven if you think “blue” when you think topaz. In fact, if you search online for “topaz,” almost the only jewelry that comes up is set with blue topaz.

ABOVE: This natural bicolor blue and colorless topaz is set in a 14k white gold. Photo by John S. White.

But until the mid-to-late 1970s, natural blue topaz was a rarity. Yellow, golden, golden-brown or “sherry” was the color that came to mind when topaz was mentioned.

This 1.48 ct blue topaz designed by Jerry Bartlemay, and titled “Spinwheel” is based on Charles Covill’s Windwheel design. Photo by Jim Lawson.

Enter a new use for irradiation treatment.

There is a lot more colorless topaz mined than topaz in desirable colors. So someone (it’s unknown who) started trying to convert that colorless topaz into something more salable. And profitable.

Somehow they discovered that irradiation would turn colorless topaz into a greenish brown. Good, but not great. But heating the resulting stones, ah, that was genius! Bingo, blue.

Blue topaz and sterling silver earrings. Blue topaz is one of the most popular jewelry stones on the market today. Photo by John S. White.

Today, literally tens of millions of carats of blue topaz are produced every year. Hardly a wonder that it’s found everywhere, and that everyone now thinks of topaz as a blue stone. (Note that virtually every blue topaz on the market has been treated. If someone is purporting their blue topaz to be “natural,” and it’s not a sky-high price, beware.)

Blue topaz is so ubiquitous—and popular—that some merchants are touting it as an alternate birthstone for December! (Jewelers of America, which is responsible for starting the modern birthstone list in 1912, officially lists turquoise, blue zircon, and tanzanite as December birthstones.)

The color of these treated stones is stable under normal wear. However, jewelry makers should not get these stones near a torch or that beautiful blue color will vanish. (You wouldn’t do it anyway because topaz can shatter with too much heat.)

If the word “irradiation” makes you nervous, you needn’t be. First, the Nuclear Regulatory Commission (NRC) keeps a close eye on irradiated products going onto the market. While blue topazes are “hot” for a few hours after treatment, they are very “cold” before they reach your suppliers’ or jewelers’ shelves. The only thing left is their lovely color.


Sharon Elaine Thompson is a GG and FGA who has been writing on gemstone and jewelry topics for Lapidary Journal Jewelry Artist since 1987. She also writes a line of Birthstone Romances under the name Liz Hartley.


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