How to Buy a Genuine Topaz

The overwhelming majority of blue topaz on the market — sold under names like London Blue, Swiss Blue, and Sky Blue — is irradiated and heat-treated from colorless (or pale) rough, a completely standard, legal, and disclosed industry practice that makes blue topaz one of the most affordable colored stones available. This is worth understanding clearly before you buy: you're very rarely paying for a rare natural blue in this category, you're paying for a well-executed, inexpensive treatment, and that's a legitimate trade as long as it's disclosed.

Because treatment status splits this gem family into two very different markets, it's the single biggest factor in evaluating topaz. Within treated blue topaz, color depth (London Blue's deeper tone typically commands more than paler Swiss or Sky Blue) and clarity drive modest price differences. Within natural-color material — especially Imperial topaz's rare orange, pink, and peach hues — color saturation is the dominant value driver, and untreated origin carries a real, substantial premium over the vastly more common treated blue material, alongside the usual clarity and carat weight considerations.

If you're buying blue topaz, treat it as an affordable, cheerful colored-stone option and don't expect natural-color rarity to factor into the price — it won't, because you're very likely looking at treated material regardless of price point. If you're specifically seeking Imperial topaz, insist on a certificate confirming natural, untreated color, since this is where the real value in the topaz family actually lives and where misrepresentation is most costly to fall for.

For certification specifics, see our Topaz certification guide, or check current Topaz prices. General authenticity standards that apply across every gemstone we handle are covered on the site-wide Authenticity & Certification page.