Opals are beautiful gemstones that are highly valued for their unique play of colour. However, due to their rarity and value, there are many imitations and synthetic opals on the market. If you have purchased an opal pendant and want to verify its genuineness, here are five ways to do so:

1. Check for Play of Colour: Genuine opals have a unique play of colour that is caused by the diffraction of light through the silica spheres in the stone. If your opal pendant has a bright and colourful play of colour that changes as you move it around, it is likely genuine.
2. Look for Natural Inclusions: Natural inclusions, such as tiny cracks or lines, are often present in genuine opals. These inclusions are a result of the natural formation process and can help you verify the authenticity of your opal pendant.
3. Check for Consistency: Genuine opals are consistent in colour and pattern throughout the stone. If your opal pendant has uneven or inconsistent colours or patterns, it may be a fake.
4. Conduct a Scratch Test: Opals have a hardness of 5.5-6.5 on the Mohs scale, which means they are relatively soft and can be scratched easily. Try scratching your opal pendant with a piece of glass or a metal object. If it scratches easily, it is likely a fake.
5. Get a Certificate of Authenticity: A certificate of authenticity from a reputable gemstone pendants dealer or jeweller can help you verify the genuineness of your opal pendant. The certificate will confirm that the opal used in the pendant is genuine and may include details about its origin, quality, and value.

In conclusion, verifying the genuineness of your opal pendant is important to ensure that you are getting what you paid for. Checking for play of colour, natural inclusions, consistency, conducting a scratch test, and getting a certificate of authenticity are all effective ways to verify the genuineness of your opal pendant. By doing so, you can enjoy your beautiful and unique opal pendant with confidence.