Diamonds come in every color of the spectrum and while we are fascinated by black and “cognac” hues, we find the most breathtaking diamond material is the one which is completely free of Nitrogen or Boron, otherwise classified as Type IIa.
This particularly vibrant and pure material was originally found in the territory known as the "Kingdom of Golconda", located steps outside the state of Hyderabad in southern India. This region is known in the trade as Golconda, referencing the fabled mines that were exhausted by 1725.
Golconda diamonds were typically cut in oval, navette, cushion, and other fancy shapes that very often do not have perfect proportions or outlines. In fact, a Golconda diamond’s charm resides precisely on their irregularities.
According to the Gemological Institute of America, less then 2% of the entire worldwide diamond production is known to have the exceptional transparency and absence of color characteristics that the Indian Maharajas and European Royals were describing as “perfect water” and “fire”.
Famous Type IIa Golconda diamonds include the Koh-I-Noor diamond, at the center of the Queen Mother's crown in the Tower of London; the Regent diamond, which once adorned the hilt of Napoleon's sword; and the Hope Diamond in the Smithsonian Museum.