Gem-set bird brooch with green garnets and sapphires

• 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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• Cabochon Cut in Jewellery - A cabochon cut is a type of gemstone cutting where the stone is cut and polished in a convex shape with a flat bottom and a domed top, with no facets. This type of cut is typically used for opaque or translucent stones that have natural patterns or inclusions that are best displayed in this type of cut. Examples of stones that are often cut as cabochons include turquoise, opal, and moonstone.
• Onyx - Onyx is a form of agate, used from antiquity and popular again in the 1920s and 30s. European onyx is generally green, but can be many other colours, and can contain bands of black and/or white.
  
  This multicoloured stone is widely used for table tops, lamp bases and in jewellery. Some types of onyx are also used for cameos of which the upper white layer is cut away to reveal the colour beneath.

This item has been included into following indexes:

• brooches, depicting - bird 221
• brooches, diamond
  • diamond and garnet 39
  • diamond and onyx 44
  • diamond and ruby 435
  • diamond and sapphire 417
• brooches, gold
  • gold with rubies 675
  • gold with sapphires 612