Golconda Diamond

“Golconda” is a historic term that refers to the area around the city and fort of Golconda in south central India, in today’s state of Hyderabad, where large diamonds exhibiting a superior quality originated. They are very rarely encountered in the gem trade today. They display singular properties typical of the scarce type IIa natural diamonds (a chemically very pure type of natural diamond). They display a colour and degree of transparency which are particular to the finest of these unique gemstones.

 

The characteristics of diamonds that are considered as Golconda- type by the Gubelin Gem Lab include:

  • Clarity: flawless, internally flawless (IF), or potentially IF
  • Colour: colourless diamonds with a D color grade. Other colours such as fancy blue are considered only for some specific historic diamonds with a well documented provenance (such as the blue Hope or the pink Grand Condé)
  • Size: minimum weight 5.00 ct
  • Diamond type: Type II
  • Shape: old cuts, e.g cushion shapes, pear-shapes. Modern cut diamonds such as round brilliant stones cannot qualify for Golconda
  • Cut: a Golconda diamond must have an antique flair, i.e. it exhibits several features which are typical for antique cuts (before 1920)
  • Treatment: diamond must be natural, i.e. spared from any treatment (e.g. HPHT)