Editing Kimberlite (section)

== Economic importance ==

Kimberlites are the most important source of primary [[diamonds]]. Many kimberlite pipes also produce rich [[alluvial]] or [[eluvial]] diamond [[placer deposit]]s. {{As of|2014}} about 6,400 kimberlite pipes are known on Earth including about 900 that have been found to contain diamonds, with mining of diamonds occurring at about 30 pipes.<ref name=Mining.com>{{cite web|title=Diamond investing FAQ|url=http://www.mining.com/diamond-investing-faq-40055/|website=MINING.com|access-date=30 August 2017|date=18 February 2014}}</ref>

The discovery of diamond-rich kimberlite pipes in northern Canada during the early 1990s serves as a prime example of how challenging these deposits can be to locate, as their surface features are often subtle. In this case, the pipes were hidden beneath ice-covered shallow ponds, which filled depressions formed by the softer kimberlite rock eroding slightly faster than the surrounding harder rock.<ref>{{Cite web |date=2024-05-08 |title=Secrets Beyond the Sparkle |url=https://www.americanscientist.org/article/secrets-beyond-the-sparkle |access-date=2024-09-05 |website=American Scientist |language=en}}</ref>
 
The deposits occurring at [[Kimberley, Northern Cape|Kimberley]], [[South Africa]], were the first recognized and the source of the name. The Kimberley [[diamond]]s were originally found in [[weathering|weathered]] kimberlite, which was colored yellow by [[limonite]], and so was called "yellow ground". Deeper workings encountered less altered rock, [[serpentinite|serpentinized]] kimberlite, which miners call "blue ground". Yellow ground kimberlite is easy to break apart and was the first source of diamonds to be mined. Blue ground kimberlite needs to be run through [[rock crusher]]s to extract the diamonds.<ref name="Schumann 2006 p. 88">{{cite book | last=Schumann | first=W. | title=Gemstones of the World | publisher=Sterling | year=2006 | isbn=978-1-4027-4016-9 | url=https://books.google.com/books?id=uXCzger619QC&pg=PA88 | access-date=2022-07-15 | page=88}}</ref>
[[File:Mirny in Yakutia.jpg|thumb|Mir mine]]
See also [[Mir Mine]] and [[Udachnaya pipe]], both in the [[Sakha Republic]], [[Siberia]].

The blue and yellow ground were both prolific producers of diamonds. After the yellow ground had been exhausted, miners in the late 19th century accidentally cut into the blue ground and found gem-quality diamonds in quantity. The economic situation at the time was such that, with a flood of diamonds being found, the miners undercut each other's prices and eventually decreased the diamonds' value down to cost in a short time.<ref>"South Africa: A New History of the Development of the Diamond Fields" (1902): New York Times Archives, ''New York Times''.</ref>