The Duke of Devonshire Emerald is one of the largest and most famous uncut emeralds in the world, weighing an incredible 1383 carats. It is in the collection of the British Natural History Museum. It is a hexagonal crystal, approx 5cm by 5cm. It was discovered in the early 19th century in Muzo, Colombia. Around that time, […]

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The largest faceted diamond in the world, at 545 carats, the Golden Jubilee outweighs even the historic Cullinan I diamond by 15 carats, but, surprisingly, is not terribly famous, despite its size and importance. It was discovered in 1985, in the Premier Mine in South Africa, the same mine that produced the Cullinan Diamond in […]

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Oftentimes it can be hard to place the exact age of a piece of jewellery, as styles evolved slowly and organically over time. In a world without mass media, the diffusion and mixing of ideas and patterns was a slow and irregular process. Nonetheless, we can divide most jewellery into a few broad categories over […]

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Perhaps the most fun and intersting ways we can age and date very old jewellery is through artwork. Almost always signed, we can normally tell exactly which year a piece of art was painted in, unlike jewellery which is rarely signed or dated! It’s also wonderful to see how people wore jewellery, what type of […]

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An interesting recent project was a restoration of a sapphire and diamond three stone ring; over 100 years old, the claws had worn away, and the sapphire had become scratched. Although sapphires are exceptionally strong and tough, over a lifetime they can become scratched. In this case, long time wearing had scratched all of the […]

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The Cullian III and Cullinan IV are the third and fourth largest stones cut from the largest diamond ever found, the 3,106 carat Cullinan Diamond. (The largest diamond produced from it is The Star of Africa). Cullinan III is a 94 carat pear shape diamond and Cullinan IV is a 63 carat square cut brilliant diamond, also known […]

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The Dresden Green Diamond is one of the rarest diamonds in the world, both in terms of its characteristics and of its provenance. Perhaps only the Hope Diamond can match its wonderfully documented history. It is a modified pear shape brilliant cut diamond weighing approximately 41 carats, and is the largest natural green diamond ever […]

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Henry Morse (1826-1888) was a famous diamond cutter in Boston, who was responsible for major advancements in the science and skill of diamond cutting. He was taught by Dutch specialists, and although originally interested in cutting the largest diamond, he quickly moved to learning to cut the most beautiful diamond possible, even if that meant […]

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The Shah Jahan diamond is a 56 carat table cut diamond, flat in general shape, perhaps (probably?) originally a cleavage piece that had been faceted. It is two inches long, but only one-eighth of an inch thick. It has two drill holes, to allow wire or cord to be passed through, enabling it to be […]

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Iolite is a precious gemstone form of cordierite, named after the French geologist Pierre Louis Cordier in 1813. It is a blue to violet colour, similar to Sapphire or Tanzanite. With a hardness of 7 to 7.5, it is softer than sapphire, but harder than tanzanite. Its name comes from the Greek words Ios, meaning […]

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