Kimberlite – Harry & Co Jewellery

Morphology and Volcanology

Kimberlite structures are emplaced as carrot-shaped, vertical intrusions termed pipes.
The carrot shape is formed due to a complex intrusive process of kimberlitic magma.
Kimberlite classification is based on differing rock facies associated with specific magmatic activity.
The morphology of kimberlite pipes is the result of explosive diatreme volcanism.
Kimberlite pipes can have a sheeted dyke complex and range in diameter from 75 meters to 1.5 kilometers.

The location and origin of kimberlitic magmas are subjects of contention.
Kimberlites have been classified into basaltic and micaceous varieties based on petrographic observations.
Later revisions led to the classification of group I and group II kimberlites.
Group II kimberlites were reclassified as orangeites due to their closer affinities to lamproites.
Group I kimberlites are CO-rich ultramafic potassic igneous rocks with specific mineral assemblages.

Group I kimberlites are dominated by primary forsteritic olivine and carbonate minerals.
They exhibit a distinctive inequigranular texture caused by macrocrystic and megacrystic phenocrysts.
The groundmass mineralogy is dominated by carbonate and significant amounts of forsteritic olivine.
Group I kimberlites have a fine- to medium-grained groundmass.
They contain trace minerals such as magnesian ilmenite, chromium pyrope, and phlogopite.

Olivine lamproites were previously called group II kimberlites or orangeites.
They are ultrapotassic, peralkaline rocks rich in volatiles.
Olivine lamproites are characterized by phlogopite macrocrysts and microphenocrysts.
The groundmass micas in olivine lamproites vary in composition.
Primary phases in the groundmass include zoned pyroxenes, spinel-group minerals, and Sr- and REE-rich minerals.

Kimberlites contain mineral species that indicate formation under high pressure and temperature.
These minerals serve as indicators of mantle conditions.
Some of these indicator minerals include chromi
The presence of these minerals is used in diamond exploration.
The chemical compositions of these minerals provide valuable information about the deep mantle.

Reference	URL
Glossary	https://harryandcojewellery.com.au/blogs/glossary/kimberlite
Wikipedia	http://en.wikipedia.org/wiki/Kimberlite
Wikidata	https://www.wikidata.org/wiki/Q204376
Knowledge Graph	https://www.google.com/search?kgmid=/m/0q015