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Know your diamond

  • Diamond experts advice service

In our studio as diamond experts, we are dedicated to offering you the best possible service.

We will advise you about your Rudolf Heltzel engagement ring and which diamond will complement your individually chosen unique design.

Why diamonds are so valuable

  • Diamond is the hardest of all gemstones known to man, born billions of years ago deep within the earth.
  • They are rare because only a few survive the hazardous journey from enormous depths to the earth’s surface.
  • The precision with which the diamond is cut determines its brilliance, its fire and its beauty

The shape you select is a matter of your individual taste. Our skill and imagination as designers and craftsmen will show off the diamond to its best advantage in a piece of jewellery created especially for you!

All diamonds are precious, but no two stones are alike. The carat-weight, the quality of cut, colour and clarity.


4 characteristics that determine the quality of a diamond


  • Cut is the only diamond characteristic directly influenced by man – the other three are directed by nature.
  • A good round brilliant-cut releases the life, fire and sparkle of a diamond through the arrangement and proportions of its 57 or 58 facets (tiny planes that create angles to reflect light).
  • When a diamond is cut to good proportions, light will reflect from one facet to another and disperse through the top of the stone, resulting in a display of brilliance and fire.
  • Diamonds that are cut too deep or too shallow lose light that spills through the side or bottom.
  • The shape of a diamond is a matter of personal taste, with the round brilliant cut the most popular of the shapes.
  • Other shapes are the emerald cut, pear shape, marquise, princess cut, oval and heart shape.


  • While most diamonds appear white, many of them display hints of colour barely discernible to the naked eye.
  • The closer a diamond approaches colourless, the better and more valuable the stone.
  • Diamonds with a strong pure colour are extremely rare and are called ‘fancies’. Amongst them can be found pink, blue, yellow, green and orange.


  • A diamond is determined by the degree to which it is free from naturally occurring inclusions, often called nature’s fingerprints.
  • The number, type, colour, size and position of the internal birthmarks can affect a diamond’s value.
  • However, many are invisible to the naked eye requiring magnification under a standard 10x magnification loupe before they become apparent.
  • The fewer inclusions, the rarer the stone.


  • Carat refers to weight and therefore the size of the diamond.
  • One carat is divided into 100 points.
  • Therefore, a diamond weighing 50 points is half a carat.
  • Size is the most obvious factor in determining the value of the diamond.
  • But two diamonds of equal size can have very different values, depending on their cut, clarity and colour.