Antique Emerald and Diamond Half Hoop Ring

• Carat - A carat (abbreviated "ct") is a unit of measurement used to describe the weight of a diamond or other gemstone, and separately is a unit of measurement used to describe the weight of precious metals such as gold,.
  
  For gemstones, one carat is equal to 0.2 grams or 200 milligrams. The weight of a diamond is one of the Four Cs (along with cut, colour, and clarity) that are used to determine a diamond's value.
  
  It is important to note that a diamond's weight does not necessarily correspond to its size. A diamond's cut, which affects how well it reflects light, can make a diamond of a lower weight appear larger than a diamond of a higher weight. Additionally, the carat is not the only factor to determine the value of a diamond, other factors such as clarity, colour and cut are important too.
  
  In the gold industry, the purity of gold is measured in carats (abbreviated "ct"), with 24 karats being pure gold and lower carat numbers indicating a lower purity level. So, for example, 18 carat gold is 18/24 or 75% pure gold, and 12 carat gold is 12/24 or 50% pure gold.
• Brilliant Cut - In their naturally occuring state diamonds have little life or sparkle and for many centuries were simply cut in half and worn in amulets. Invented at the end of the 17th century by a Venetian diamond cutter, a "brilliant cut" diamond has 58 facets arranged in a regular geometric relationship, with 33 above the crown and 25 below on the pavilion.
  
  The introduction of the brilliant cut increased the popularity of diamonds in jewellery as it was the first cut to reveal the fire of the diamond, with the light being internally reflected from one facet to another, and was superior to the previously used table cut and rose cut.Variants to the brilliant cut have emerged since the end of the 17th century, but the popularity of the original brilliant cut has continued to the present time, where it is still the most commonly found cut.
  
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• Emeralds - Emeralds have been used in jewellery making for thousands of years, and are prized for their deep green colour, which is caused by the presence of chromium and vanadium in the mineral beryl. Because of their rare colour, emeralds are often more valuable than diamonds of a similar size and quality. In jewellery making, emeralds are typically cut into round or oval shapes to maximize their color and clarity. They are often set in gold or platinum and used as the centrepiece of a piece of jewellery, such as a ring or necklace. They can also be used in combination with other gems, such as diamonds, to create intricate and beautiful designs.
• Rose Cut - A flat based cut for a preious stone, leaving the surface covered with triangular facets, usually 24 in total.
  
  It was introduced in the 15th century and popular during the 16th and 17th centuries.
  
  The rose cut was the most popular form of diamond cut until the discovery of the brilliant cut at the end of the 17th century, after which its use declined.

This item has been included into following indexes:

• rings, diamond
  • diamond and emerald 1,173
  • diamond and emeralds 2,162