GIA Diamond Formation, Mining, and the Diamond Market

Question 1

Where do most natural diamonds form?

Accepted Answer

In the Earth’s mantle

Answer

Natural diamonds form deep within the Earth's mantle, approximately 90 to 120 miles (140 to 190 kilometers) below the surface. This process requires extreme conditions of high temperature (over 2,000°F or 1,100°C) and immense pressure, which cause carbon atoms to crystallize into the diamond structure. These diamonds are then brought closer to the surface through deep volcanic eruptions.

Question 2

What is kimberlite?

Accepted Answer

Volcanic rock bearing diamonds

Answer

Kimberlite is a type of igneous rock that originates deep within the Earth's mantle and is the primary host rock for diamonds. It forms through explosive volcanic eruptions that bring diamonds from the mantle to the Earth's surface in pipe-like formations. These kimberlite pipes are the most significant source of primary diamond deposits worldwide.

Question 3

Which country is one of the largest producers of diamonds by volume?

Accepted Answer

Russia

Answer

Russia is consistently one of the world's largest producers of natural diamonds by volume, with extensive mining operations primarily in the Siberian region. Companies like ALROSA contribute a substantial portion of the global rough diamond supply. Its vast diamond reserves and advanced mining infrastructure make it a dominant player in the international diamond market.

Question 4

What role does the De Beers Group play in the diamond industry?

Accepted Answer

Dominated global supply and marketing

Answer

For much of the 20th century, the De Beers Group held a near-monopoly on the global diamond supply, controlling a vast majority of rough diamond production and distribution. Through strategic marketing campaigns, such as 'A Diamond Is Forever,' they also significantly influenced consumer demand and perceptions of diamonds. While their market share has decreased, their historical dominance shaped the modern diamond industry.

Question 5

What is alluvial diamond mining?

Accepted Answer

Extracting from waterways and sediments

Answer

Alluvial diamond mining involves recovering diamonds that have been eroded from their primary source (like kimberlite pipes) and transported by natural forces, such as rivers, streams, and ocean currents. These diamonds accumulate in secondary deposits like riverbeds, beaches, and ancient floodplains. Miners typically use methods like panning, dredging, or sifting to extract diamonds from these loose sediments.

(GIA) Certified Diamonds Gemological Institute of America Practice Test

(GIA) Certified Diamonds Gemological Institute of America Practice Test

GIA Diamond Formation, Mining, and the Diamond Market