French 18ct Gold Three-Coloured Snuff Box, 1800

• 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.
• Engine Turned - Engine turning is a decorative technique used on metal surfaces to create intricate curving or geometric pattern. The process involves cutting a series of lines into the surface of the metal using a rose engine or decoration lathe which rotates the metal as it cuts, allowing the operator to create a repeating pattern that covers the entire surface. The resulting surface has a shimmering, reflective quality that is often described as "engine turned." Where an engine turned item has been enamelled, the term used to describe the decoration is usually guilloche.
  
  Engine turning was originally developed to decorate metal objects such as firearms, scientific instruments, and other metal objects that required precise and elegant design.
• 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.

This item has been included into following indexes:

• snuff boxes, material - gold 72