The best way to gain an overview of what differentiates these is to look at the IUGS classification of igneous rocks ( Le Maitre (Ed), 2002. ISBN 0521 66215 X.).

If you have trouble accessing this then please feel free to contact me. Relevant sections are:-

Kimberlites 2.6

Lamproits 2.7

Lamprophyres 2.9

As a further reference the Glossary of Geology is recommended:

Glossary of Geology, 5th Edition

by Klaus K. E. Neuendorf (Editor), James P. Mehl Jr. (Editor), Julia A. Jackson (Editor)

ISBN-13: 978-0922152766

ISBN-10: 0922152764

Dear madam Horak, I am not able to access this article. Can you kindly send me a copy to my email [email protected] or here. Thank you.

Yes of course I  may not be able to do this immediately but I will do my best.

You can recognize these rocks in the filed and in microscope. They have different

Kimberlite occurs mainly in craton, and lamproite in the margin of craton. Lamproite is volcanic rock composed mainly of olivine, clinopyroxene (diopside), mica, leucite, K-amphibole, sanidine. There are many types of lamproite. Geochemically: 

SiO2-40-65%, Al2O3 - 5-12%, MgO -30-5%,  K2O - 3-12%,   MgO>CaO,     K2O>>Na2O.

Kimberlite is enriched in CO2), hig K, ultramafic,  fine-grained matrix contain olivine, ilmenite, diopside, garnet, flogopite, enstatite, chromite as macrocrystals or xenocrystals and xenoliths. There are two groups of kimberlite

Lamprophyres are different rocks, subalkline and alkaline. They have porphyritic texture with relatively large phenocrysts of mica or amphibole, or pyroxene.  In the groundmass  plagioclase and K-feldspar (olivine).

Dear colleagues,

another answer from the point of view of an economic geologist:

1. Lamproite-group rocks are dark-colored magmatic rocks enriched in K and Mg and hypabyssal or effusive in origin. Lamproites are peralkaline ultrapotassic Mg-enriched magmatic rocks with all hallmarks of ultrabasic rocks such as elevated Cr and Ni contents ( Mitchell 1991). They may contain leucite, phlogopite, and glass (fizroyite), plogopite, diopside, leucite (wyomingite) or phenocrysts of diopside and phlogopite in a fine-grained glassy matrix which chemically can be approximated to the composition of leucite (madupite). They may also contain amphibole, olivine, sanidine, spinel, apatite and nepheline together with some wadeite and priderite.

2. Kimberlite-group rocks are close to porphyritic alkaline peridotites. They contain phenocrysts of olivine which frequently serpentinized, phlogopite converted into chlorite, geikelite (= "Mg ilmenite"), and. chromian pyrope-enriched garnet. They float in a fine-grained matrix of calcite, olivine, and phlogopite (2 nd gen.). Accessory minerals are ilmenite, magnetite, spinel, monticellite, apatite and perovskite. Chrome diopside mineralization in kimberlites is an important guide to diamond deposits. Kimberlite is by definition a K-enriched ultramafic rock which derived from a depth of more than 150 km below surface (Clement and Skinner 1985, Kirkley et al. 1991). Moving upwards, the hypabyssal intrusions grade into diatreme breccias and pyroclastic rocks

3. Lamprophyre-group magmatic rocks are dark-colored like the afore-mentioned subcrustal rocks abundant in biotite, hornblende, pyroxene, present as phenocrysts in a fine-grained matrix of K and Na/Ca feldspar and/ or feldspathoids. According to the abundance of these minerals mentioned above they are subdivided into minette, kersantite, spessartite, camptonite, monchiquite, fourchite and alnoite.

No 1 - rocks are host of diamonds predominantly in Western Australia.

No-2- rocks are host of diamonds predominantly in Tanzania, Botswana, Angola, DR Congo, South Africa, Russia, Lesotho, Canada, Zimbabwe, Greenland, Gabon (metakimberlites)

No -3 - rocks gave besides diamonds (Michipicoten and Abitibi greenstone belts) also host to sapphire in Yogo Gulch, Montana, USA. It takes an outstanding position as it is bound to lamprophyre dykes classified as ouachitite ,a biotite monchiquite devoid of olivine with a glassy or analcime-bearing groundmass.

Best regards

Harald G.Dill

Dear colleagues,

I'm so sorry, but geology is not my domain, and I can't you help.

The distinction between lamprophyres and lamproites is not an easy task. Also IUGS does not give definitive and clear rules to distinguish these rock types.

As an example, Oligocene lamproitic rocks from N Italy are indeed lamprophyres, and Late Cretaceous lamproitic rocks from SE Brazil (Presidente Olegario) are instead kamafugites (ultrapotassic kalsilite-bearing volcanic rocks).

The main problem is that these rocks are highly porphyritic and the whole-rock composition strongly depends on the local abundance of a given mineral.  This is particularly true for kimberlites, characterized also by abundant presence of mantle xenocrysts and xenoliths.

Moreover, many lamproites are old and severely wheatered, lowering the classification power of whole-rock chemical analyses.

Olivine lamproites are very different from phlogopite lamproites in terms of incompatible element content an diamond grade (nearly all the diamonds are associated to olivine lamproites rather than phlogopite lamproites).

A last comment: officially lamproites are peralkaline (molar Na+K > Al) and perpotassic (molar K > Al) rocks, but more than half of the rocks classified as lamproites in literature do not match these definitions (i.e., they are metaluminous). Moreover about half of the "classical" lamproites (i.e., those defined as "anorogenic") have a quite low K2O content, associated to much higher Na2o (i.e., they are sodic instead potassic-ultrapotassic).

In primitive mantle-normalized diagrams circum-Mediterranean lamproites, silica-undersaturated ultrapotassic rocks (e.g., leucitites) and silica-oversaturated potassic to ultrapotassic rocks (e.g., latites, shoshonites) are nearly indistinguishable each other. On the other hand, kamafugites and anorogenic lamproites share many incompatible element similarities.

In conclusion: the distinction among these three main rock group is possible, but is never an easy task.

michele

A comment on my previous message.

the text I wrote "Moreover about half of the "classical" lamproites (i.e., those defined as "anorogenic") have a quite low K2O content, associated to much higher Na2o (i.e., they are sodic instead potassic-ultrapotassic)." is wrong. The official lamproites (i.e., those from Gaussberg, Antarctica), also defined in literature as "anorogenic" are effectively ultrapotassic, peralkaline and perpotassic (at least the great majority of them). So delete what I have written. I simply inverted the Na2O with K2O for some analyses in my database.

The "exceptions" are the "orogenic lamproites", essentially those from the Mediterranean area. Many of them are non peralkaline (they are metaluminous) and only very few are perpotassic. According to the IUGS rules these rocks should not be defined as true lamproites.

You will find the answer in the the attached paper by Tappe etal 2005 for  IUGS classification of lamprophyres and associated rocks

SEE THE IUGS CLASSIFICATION (WOOLLEY ET AL. 1996, LE MAITRE ET AL. 2002).