Antique Australian Gold Buckle Brooch with Enamel and Pearls

• Circa - A Latin term meaning 'about', often used in the antique trade to give an approximate date for the piece, usually considered to be five years on either side of the circa year. Thus, circa 1900 means the piece was made about 1900, probably between 1895 and 1905. The expression is sometimes abbreviated to c.1900.
• 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.
• Important - Important is a word used in the antique trade to indicate an object should be ranked above other similar objects, and is therefore more valuable.
  
  The object could be considered important because it is by a famous designer or maker, has been shown at a major exhibition, is of exquisite workmanship, is rare or is a "one-off", was made for an important patron, and so on.
  
  Even further up the pecking order are objects that are described in catalogue descriptions as highly important or extraordinarily important.
• 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.
• Filigree Work - Jewels - Filigree is delicate and intricate ornamental metal-work made from thin threads of gold or silver, soldered and twisted together to give the effect of lace. The filigree work may be freestanding, or attached to the surface of an object.
• Herringbone Link in Jewellery (component) - The herringbone link is a jewellery chain pattern that is named after the distinctive V-shaped pattern that it creates, resembling the bones of a herring fish. It is a popular and classic design that has been used in various types of jewellery, including bracelets, necklaces, and earrings.
  
  The herringbone link is characterized by its tightly woven pattern, which features rows of thin, flat metal links that are arranged in a crisscross or zigzag pattern. The links are typically angled at 45 degrees, creating a distinctive "V" shape that gives the chain its unique appearance.

This item has been included into following indexes:

• brooches, design or type - portrait and locket 507
• brooches, diamond
  • diamond and enamel 134
  • diamond and pearl 392
• brooches, gold
  • gold with enamelled decoration 385
  • gold with pearls 921
• brooches, other - with locket 753
• brooches, set with - filigree decoration 130