March 30, 2020

The History of Diamonds

In the 1st century AD, Pliny the roman naturalist stated “Diamond is the most valuable, not only of precious stones, but of all things in the world”.

While many people wear diamonds, sometimes on a daily basis, many don't know anything about them, such as the fact they are between one to three billion years old. A white diamond is made up of pure carbon, the only gem made of a single element, trace elements found in the structure can cause the diamond to show different colours. The carbon atoms are arranged in an equidistant pyramidal structure which makes it 58x harder than any other material on Earth, only a diamond can cut a diamond. The most common rough diamond shape is an octahedron, which is essentially two pyramids back to back.

Rough diamond ring yellow gold band

A 6.10 carat rough octahedral diamond set in platinum and 18K yellow gold

Diamonds are formed 100’s of kilometers below the surface of the earth, under intense heat and pressure only found in specific locations at certain depths. They are rare gemstones, in fact the average mine yield is 1 part diamond to 1,000,000 parts host rock; picture trying to find one golden ball in amongst 1,000,000 red ones. The host rock diamonds are found in is a kimberlite, a type of volcanic rock which has been violently ejected from deep within the earth, to the surface. Over time, this rock is uplifted, weathered and eroded, and the material transported away from its source. This is how diamonds were initially discovered in the rivers and lakes of India in the early 4th century BC. Diamonds are weighed in carats, which is equivalent to 0.2g, the weight of a carob seed against which they were first weighed.

The first large scale mines were in Kimberly, South Africa. The rock kimberlite was named after the town after the discovery of an 83 carat diamond named the Star of Africa, which sparked the diamond rush in 1869. De Beers first opened mines in 1888, by the 1900’s they owned 90% of the worlds’ diamond mines.

The Cullinan mine in South Africa cropped

The Cullinan Mine, South Africa.

Diamonds have a natural sparkle called scintillation which causes it to reflect and refract light in such a way that it seems to glow from within, this is also known as “fire”. The way in which the diamond is faceted impacts its’ brilliance, much research has been done into which proportions and angles create the perfect sparkle. A certified diamond will come with a cut grade, clarity grade, colour grade, carat weight and shape.

The 4 C’s were created by the GIA in the 1950’s and is today the world grading standard. Diamond colours range from D-Z, colourless-yellow. They also have 5 cut grades of Excellent (EX), Very Good (VG), Good (G), Fair (F) and Poor (P). The clarity of a diamond is how many natural inclusions it has within, the best being Flawless (Flawless), with the worst being I3 (Included 3).

GIA Clarity
GIA Clarity Scale

The most popular shape of diamond is the round brilliant. This is because when cutting a perfect octahedral rough diamond through the middle, you can produce two round brilliant cut diamonds. The shape of the rough diamond determines the shape of the polished diamond at the end. If a rough diamond isn't a perfect octahedron, fancy shapes such as cushion, oval, heart or emerald cut can be created. Generally, when cutting rough diamonds, around 50% of its carat weight is lost to the cutting process.

Diamond Cut Process

Diamonds have been used in jewellery since the roman times and earlier, however, the first recorded diamond engagement ring was given to Mary of Burgundy in 1477, it was an initial “M”, set with rose cut diamonds. Since then, diamonds have been set in pretty much everything from watches to headphones, and loafers to handbags.

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Category

Gemstones

Tags

  • Education
  • jewellery

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