Geology of Natural Colored Diamonds

Natural colored diamonds are formed as a result of the contamination or exposure of the diamond to certain elements during the process of their formation. Other factors that result in the appearance of color, in an otherwise colorless diamond, are extremely high temperatures beneath the earth’s surface as the diamond is forming as well as the exertion of pressure on the stones.

The presence of these factors depends largely on the place where the colored diamonds are found. Different types of geographical locations will produce different types of colored diamonds. Hence, there is definitely a correlation between geology and the formation of colored diamonds. Here is a rundown of various mines around the world and the type of colored diamonds they produce.

In Angola, where diamond mining began in 1912, produces fancy yellow, intense yellow, brown and pink diamonds. The diamonds found here are extremely large in size, weighing over two hundred carats most of the time.

In Argyle, a diamond mine located in Kimberly, Australia, purple pink, pink, brownish pink, pink champagne, champagne and brown diamonds are abound. This mine is unquestionably the largest producer of diamonds in the world. It produces ninety-five percent of the world’s pink diamonds. Hence, if you find yourself looking at a pink diamond, it is most likely from the Argyle mine.

Borneo diamonds are more diverse in color, ranging from yellow to brown to pink, blue and green. In Minas Geraes, Sao Paolo in Brazil, you will find the rarest colored diamonds—the red diamond. Minas Geraes is a mining district, as are Matto Grosso and Bahia. There are many colored and colorless diamonds to be mined here; however, most of them are not gem quality.

The Ekati and Diavik mines in Canada produce colorless diamonds and the occasional yellow diamond. The Central African Republic produces almost every color in the diamond spectrum: yellow, olive, pink, black, blue, green and brown diamonds. That is why the mines in the Central African Republic are very important to the diamond industry.

China also produces colored diamonds in light pink and medium pink shades. However, it is still colorless diamonds that are mainly found in China. The Democratic Republic of Congo has brown, gray, olive, yellow, cognac and orange diamonds. There are a lot of diamonds to be mined here; however, they are mostly not of gem quality.

In Guinea Cape, yellow and pink diamonds are a common find, and they are large in size too, weighing in mostly at one hundred carats apiece. Guyana is the source of the exquisite turquoise and aquamarine diamonds. It is interesting to note that Guyana miners still use the old-fashioned method of river mining using sluice boxes.

The Ivory Coast produces greenish-yellow, yellow and brown diamonds. The aforementioned greenish-yellow diamonds are also found in Venezuela.  Of course, there is also Russia, which produces grayish-yellow, purple and brown diamonds. Their mines are found in Siberia, where colorless diamonds of high quality are also sourced.

Sierra Leone is also another well known diamond producer, where yellow and olive green diamonds can be found. Meanwhile, South Africa produces a whole range of colored diamonds like the cape, blue, yellow, pink, green, brown, orange, cognac, purple and black diamonds.