Frequently Asked Question about Diamonds
What is a diamond?
Diamond, the hardest known material is pure carbon, crystallised under a very high pressure and temperature. In nature, such an environment exists only at depths of 150 to 200 km below the surface of the earth. Volcanic eruptions drive the diamond bearing rocks called ”Kimberlite” and ”Lamproite” to the surface of the earth where the diamonds can be extracted.
Where are the main diamond sources?
Throughout history people have always been fascinated by the beauty and mystery of diamonds. Until the 18th century, India was the only source of diamonds in the world. In the second half of the 19th century, the first diamonds were discovered in Africa and soon after, a ”diamond rush” started. The first diamond diggers worked individually by hand, but when the pits became deeper, large mining companies were established, exploiting the diamond mines with mechanical equipment. Today, the most important diamond supplying countries are Australia and Congo for industrial diamonds and Southern Africa, Australia, Congo, Russia, Namibia and Botswana for gem quality stones.
How are diamonds mined?
The mining methods are very diverse, depending on how diamonds present themselves at the earth’s surface. Mining of Kimberlite pipes involves ”open-pit” or ”underground mining”. When freed by erosion from the Kimberlite matrix, diamond crystals are carried along by rivers. Riverbeds are dug away and the river silt is sieved. This technique is called ”alluvial mining”. ”Marine mining” is the exploitation of sandy coastal strata by dredging. Finding diamonds can thus be the result of large industrial operations, but also of small-scale methods, or even manual labour. Diamonds are rare. It is usual that 250 tons of rock, sand and gravel must be processed to yield one carat of diamond. The annual world production amounts to approximately 100 million cts of which only 20% are of gem quality.
How are diamonds transformed from rough to polished?
A rough diamond obtains its final shape and brilliance by a succession of manufacturing processes : cleving, sawing, bruting and polishing.
How is the quality of a diamond defined?
The quality of a diamond is determined by the four C’s. Carat , Colour, Clarity and Cut.
What is a carat?
Diamonds are weighed in carats. One carat equals a fifth of a gram. The name ”carat” comes from a seed of the carob tree. The seed was called ”carubis” and had an approximate weight of about 0.2 grams.
Why is craftsmanship in diamond processing so important?
A diamond can be loupe clean and have the best white colour, but if the facets of the stone have not been placed in perfect harmony, then there is no shine, no fire in the stone. The label ”Cut in Antwerp” is a quality label refering to the best diamond cut in the world.
Which are the most famous diamonds in the world?
The Cullinan I: a pear shaped diamond of 530.20 carats also called ”The Star of Africa”. Set in the English crown jewels. Can be admired in the Tower of London.
The Koh-I-Noor: This ”Mountain of Light” is the oldest of the famous diamonds, has an oval shape and weighs 108.93 carats. Discovered in India, the stone is now part of the Crown Jewels in the Tower of London.
The Hope: This is a blue diamond of 44.50 carats and with a remarkable brilliance. At the moment, the stone is on display at the Smithsonian Institute in Washington. It had the reputation of bringing misfortune.
What is the economic importance of Antwerp as World Diamond Center?
Antwerp is situated in the heart of Europe, easy to reach by car, plane or train. The diamond center is concentrated on merely two square miles near the Central Railway Station. Over 50 pct of the world production, be it rough or polished, industrial or gem quality diamonds, passes through Antwerp.
What is so special about the Antwerp Diamond District?
The diamond trade in Antwerp is conducted on a small area; the bourses and offices are lined up on a small area. When in sunny weather, the dealers come out in the street for a break and a chat, the outsider is surprised at the variety of types, colour and dress. The Jews have been present in the Antwerp diamond trade ever since the 16th century. The Orthodox Jews can easily be recognized by their black attire of the same cut, hat, beard and hairstyle. There are also other Jews, which only a trained eye can recognize as such. The other community, which is largely presented, in the Antwerp Diamond World is the Indian community. The Indians, who originally specialized in cheap goods, are gaining more experience in larger sizes. The cheap, small brilliant and single cut still comprises the lion’s share of their production. But beside these two main communities there are people from all European countries and all continents, who make their living in the diamond trade. In Antwerp all languages and dialects are spoken and this improbable symbiosis has only one thing in common: the diamond. This mosaic of ethnic cultures, life styles and religions can rely on Antwerp’s world-renowned hospitality and tolerance.
What is the Diamond High Council?
The HRD was established as a central organisation for the promotion of the interests of the diamond trade, industry and consumer.
What is the difference between a brilliant and a diamond?
This is actually a wrong question. Both cannot be compared as such. A brilliant is only a ’cut’, which means that any rough material, be it glass or diamond, can be cut into the shape of a brilliant ( 57 facets ).