Antique and vintage jewellery is a beautiful and collectable alternative to jewellery from big chain stores. But how do you know it’s real?
Here’s what we do with our pieces to ensure that you can buy with peace of mind:
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Visual inspection with unaided eye, 10x loupe and microscope: When it comes to jewellery, it’s all about the small things. We get in close and look for key details to establish the maker, gold purity and possible date or era of the piece. Some pieces have full or partial sets of hallmarks or inscriptions. Most will have purity stamps expressed either as numbers and letters (for example 9ct or 9k for 9 carat/karat gold) or as numbers to indicate the percentage of pure gold (375). Markings and inscriptions can also give an indication of period/era, or in some cases the year in which the piece was made (date letters).
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Weigh with a scale: Gold and other precious metals like sterling silver and platinum are heavy and should feel hefty for their size. A portion of the value of precious metal jewellery comes from their weight, so listings should always include weights (but many don’t!).
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Accurate measurement of gemstones: Small differences in gemstone size can make a big difference in price. We weigh loose gemstones using a carat scale, or estimate carat weight within mounts using a millimeter gauge and the correct formula based on the cut and type of gemstone.
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Test precious metals: A very traditional way of checking unmarked precious metals is an acid test. This involves scraping a thin layer of precious metal from a piece and then applying a small amount of acid to see how it reacts. X-ray fluorescence (XRF) machines can also be used for an even more accurate result. Unmarked pieces (including those without hallmarks) are not necessarily a problem and can absolutely be authentic.
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Thermal and optical tests of gemstones, including diamonds: We use thermal conductivity and optical testers as part of our authentication process. Thermal conductivity tests give an indication of what type of gemstone something could be based on the range that it falls in. Optical tests help to distinguish between diamond, moissanite, natural (earth mined) diamonds, lab created/synthetic diamonds and simulants (natural or synthetic gemstones used to look like a diamond).
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Advanced gemmological testing of gemstones: Using our gemmological training, we can use advanced tools such as a refractometer, spectroscope, dichroscope and polariscope to confirm the results of thermal/optical tests or in cases of uncertainty. All gemstones are unique and require individual attention, particularly when there are constraints such as different types of settings.
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Gemmological grading: We grade diamonds systematically using a gemmological microscope and a set of reference stones. This results in a specific statement of colour and clarity based on the GIA grading system (for example SI1 clarity, H colour).
Testing antique and vintage pieces can be time consuming and expensive (due to the cost of gemmological training and equipment), but it’s definitely worth the effort! At Goldbrick Jewels, we assess authenticity of our pieces using all of these methods to ensure that you can buy with confidence.