Diamonds may be a girl's best friend, but consumers may want alternatives. Whether it's due to cost savings, or concerns about some diamond mining and business practices, several options exist for fans of clear gemstones. These can range from cubic zirconium to Moissanite to white sapphire. Some of these are natural, some are artificial. Although a professional appraisal can help determine the differences, there are things potential buyers can do when trying to distinguish actual stones like white sapphires from synthetic gems.
Natural vs. synthetic white sapphires
Check your stone's hardness, using a jeweller's file if one is available. Actual sapphires, composed of the core mineral corundum, are considered the second-hardest stone using the Mohs scale. This industry standard for determining hardness tells us that sapphires can scratch any other mineral except diamond, and conversely, that only a diamond can scratch a sapphire.
Compare prices. While less scrupulous sellers may artificially inflate a false gem's price, true white sapphires are found less commonly in nature than blues and other colours. This rarity means the actual price is going to be high, but still generally less than a comparable diamond. Depending on quality and style cut, the average price in spring 2010 for a cut, unmounted white sapphire is around £130-£260 per carat. A fair price for an artificially-created white sapphire is much lower.
Learn the country of origin. Actual sapphires are only found in areas of Asia like Sri Lanka and Burma, a few areas in Brazil, Australia or Madagascar, and mountainous parts of the U.S., such as Montana. Be suspicious of sellers who don't know or won't disclose a gem's provenance, or who tell you it comes from an unusual location.
Study the interior colour. A pure naturally-found white sapphire can still be a little cloudy, even off-white, or have a slightly yellow tinge. A synthetic may be completely clear.
Request a formal appraisal. Jewellers have several testing tools at their disposal that the public may lack, such as refractometers, which can make chemical verification simple. While choosing a reliable jewellery appraiser can be a separate article, you should generally seek someone with proper accreditation and training in coloured stones and distinguishing synthetics.
Even some of the previous steps are not entirely foolproof, other than the appraisal. Some subjective observations, such as a "softer" vs. "harsher" colour tones, come from experience. Some synthetic sapphires, especially those intended for industrial uses, can be chemically identical to a sapphire, including similar hardness. Sellers could also charge extra for stones to make them appear rare in price to someone who hasn't adequately done their homework.