Close Menu
Modern JewelerModern Jeweler
    Modern JewelerModern Jeweler
    • News
      • Industry News
    • Events
    • Consumer Education
      • The 4Cs of Diamonds
      • Diamond Cut
      • Diamond Clarity
      • Diamond Carat
      • Diamond Color
      • Diamond Prices
      • Diamond Shapes
    • About Us
    • Contact
    Friday, June 6
    Modern JewelerModern Jeweler
    Home»Gem Profile»Irradiated Blue Topaz
    Gem Profile

    Irradiated Blue Topaz

    David FedermanBy David Federman12/08/20236 Mins Read
    Share
    Facebook Twitter LinkedIn Pinterest Email

    Dealers don’t like to admit it but blue topaz has given aquamarine, its blue beryl double, a hard time in the last few years. Indeed, lighter-shade aqua that once fetched $150 per carat has dropped considerably below $100 per carat because look-alike blue topaz was selling readily to the trade for $4 per carat. Manufacturers who couldn’t see any difference between the two stones but price took topaz. So did retailers, especially when they realized that, for $8-$10, they could buy all they wanted of deeper-shade blue topaz that rivaled $200-$400 per-carat aqua in color intensity.

    As a result, a lot of U.S. aqua sellers have had to add blue topaz to their inventories over the last few years. They were joined by hundreds of dealers all over the world racing to ride the huge wave topaz wave to America’s shores.

    And what a blue it has been. Indelible as it may seem, blue topaz has become the biggest selling non-traditional colored stone in this country. But while the gem has also scored big abroad, passion for it in foreign markets hasn’t been able to cripple aqua sales as it has done here. Dealers believe that consumers in sophisticated gem-consuming countries like Japan clearly see irradiated blue topaz as a novelty and not as an aqua substitute. In America, however, it is regarded as a full-fledged gem. But with the market virtually flooded, and prices continually dropping, demand for blue topaz may have flattened.

    Mixed Emotions

    Whatever the future for irradiated blue topaz, many gem importers who sell it will remain ambivalent about the gem, stocking it, without much enthusiasm, to accommodate customers. Granted, these dealers admit, the stone gives the look of fine aquamarine at a fraction of that gem’s price. But the fact that topaz color is produced at will using irradiation riles them. Somehow this makes the gem more a product of the laboratory than nature.

    Trade ambivalence about topaz is evident in the marketing and merchandising of the gem. Few retailers even bother to tell the public that the blue topaz it is buying by the ton owes its color to a nuclear reactor or a linear accelerator.

    Some see such non-disclosure as a coverup of radioactivity health hazards. Not so. Interviews with treaters, dealers and government officials lead us to conclude that blue topaz poses no danger whatsoever. First of all, stones treated in ways that leave residual radioactivity are quarantined (usually anywhere from three months to one year) until levels read ultra-conservatively low. By the time these stones get to jewelry stores, radioactivity is unmeasurable with conventional geiger counters. And even when the Nuclear Regulatory Commission (NRC), which licenses reactors in this country where topaz is treated, ran radioactivity tests of irradiated blue topaz using ultra-expensive and sensitive measuring devices, it found no cause for concern.

    So why neglect to tell the public about irradiation? The answer, we think, lies in the fact that the gem is a high-tech hybrid that transcends all conventional classifications. On one hand, the stone is natural, starting life as super-abundant colorless or tinted topaz from places like Brazil and Sri Lanka. On the other hand, its color is entirely manmade, due to a combination of irradiation and heating.

    Now topaz isn’t the first gem to be safely and permanently colored by irradiation. Diamonds have been subjected to this process since the late 1940s. What is new about irradiated topaz is its affordable profusion and its phenomenal success. A decade ago, when irradiated blue topaz was still a relatively new market entry, wholesale prices were around $40 per carat to bulk users. But today for the same volume buyers are charging well little as $2 per carat for light to medium tones, a few dollars more for deeper tones. The reason: over-saturation of the marketplace. That surfeit, one that dealers liken to the Linde synthetic star sapphire craze of the 1950s, has aroused predictions of a topaz bust.

    Birth of the Blues

    Blue topaz specialists resent the comparison of their product to the Linde star. They remind critics that aquamarine, the stone blue topaz resembles so strongly, is heated to remove green. But decent aqua doesn’t cost under $10 per carat. Nor is it available in anywhere near the quantity of blue topaz. Last, exposure to low-level heat is a far cry from exposure to electron and neutron bombardment.

    Nevertheless, while blue topaz is as much the creation of a lab as the Linde star, it is exhibiting more staying power. Further, dealer annoyance with the gem seems somewhat groundless. Those who complain that blue topaz has a mass-produced color sameness possible only with irradiation are probably not aware that only 20% to 30% of the stones irradiated turn a desirable color. True, the eye-shadow names like “sky blue” given to irradiated topaz hues suggest paint-chip color consistency. But such topaz, specialists assure us, is not the case. Instead, these terms are market shorthand for various irradiation techniques used.

    Treaters who want deep aqua-blue colors use neutron bombardment in a nuclear reactor and market the final product under the name “London blue.” Neutron treatment is the only means by which to produce smaller calibrated stones with deep color. If this technique is used, stones fall under NRC jurisdiction. Current NRC rules require that  neutron bombardment done in this country, regardless of gem species, be performed only by NRC-licensed reactors. If stones are reactor-treated abroad, their U.S. importers must be licensed by NRC to do so.

    However, blue topaz irradiated in any manner other than neutron bombardment escapes NRC scrutiny. That’s because other techniques involve non-residual radioactivity for which measuring decay (or half lives) is not important. After neutron bombardment, the most common irradiation technique used to color topaz is electron bombardment in a linear accelerator.

    More recently, topaz producers have combined reactor and accelerator treatment to produce an attractive color we find reminiscent of blue zircon, a stone that owes its color to heating. Ironically, several importers told us the color of these stones was “fake.”

    Treaters think this reaction is more psychological than aesthetic. They note that tanzanite, a brownish-purplish zoisite heated to turn a desirable blue, is almost never found naturally in its blue state. So what’s the difference between browning zoisite and colorless topaz? Except for price, it’s looking more and more like there isn’t any other answer to that question.

    Please note: this profile was originally published in 1988 in Modern Jeweler’s ‘Gem Profiles: The First 60’, written by David Federman with photographs by Tino Hammid.

    The 60-carat irradiated blue topaz shown in the header image is courtesy of Overland Gems, Los Angeles.

    1
    Share. Facebook Twitter Pinterest LinkedIn Tumblr Email
    David Federman

    David Federman is a seasoned jewelry writer and editor with over 40 years of experience in the industry. As an award-winning Executive Editor and journalist, he has demonstrated expertise in various facets of the jewelry world, including gems, precious metals, jewelry manufacturing, gemology, and trade regulations. David has authored four books on gems, solidifying his reputation as a trusted authority in the field.

    Related Posts

    Black Diamond

    12/15/2023

    Canary Diamond

    12/15/2023

    Cape Diamond

    12/15/2023

    Champagne Diamond

    12/15/2023

    Colorless Diamond

    12/15/2023

    Golconda Diamond

    12/15/2023

    Jewelry industry news & insights delivered straight to your inbox

    Get the free 5-minute newsletter read by Jewelry Industry professionals who want to get ahead

    Your subscription could not be saved. Please try again.
    Your subscription has been successful.
    modern jeweler wht 300

    Explore

    • About
    • Contact

    Reach Our Audience

    • Advertise
    • Submit a press release
    • Submit an opinion piece

    Consumer Education

    • 4Cs of Diamonds
    • Diamond Price Chart

    Modern Jeweler is part of Loupe Media Network

    Privacy policy | Terms of use | Cookie Policy

    Type above and press Enter to search. Press Esc to cancel.

    We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept All”, you consent to the use of ALL the cookies. However, you may visit "Cookie Settings" to provide a controlled consent.
    Cookie SettingsAccept All
    Manage consent

    Privacy Overview

    This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
    Necessary
    Always Enabled
    Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.
    CookieDurationDescription
    cookielawinfo-checkbox-analytics11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
    cookielawinfo-checkbox-functional11 monthsThe cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
    cookielawinfo-checkbox-necessary11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
    cookielawinfo-checkbox-others11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
    cookielawinfo-checkbox-performance11 monthsThis cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
    viewed_cookie_policy11 monthsThe cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.
    SAVE & ACCEPT