Diamond exploration uses certain kimberlitic indicator minerals like G10 garnet (pyrope), magnesiochromite, picroilmenite, Cr-diopside, forsteritic olivine and zircon. Are there any other indicator minerals in regard to non-kimberlitic diamondiferous rocks like olivine lamproite and orangeite?
Ioannis Kamvisis
DEAR MICHAEL
THANK YOU FOR YOUR REPLY. I THINK YOU ARE RIGHT. ILMENITE IS FOUND AS A DETRITAL MINERAL TOGETHER WITH DIAMONDS IN CEMPAKA IN BORNEO (WRIGHT ET AL. 2016). IT IS ALSO FOUND IN THE URALS (LUKYANOVA ET AL. 1998).
BEST REGARDS
IOANNIS
DEAR MICHAEL
THANK YOU FOR YOUR REPLY. I THINK YOU ARE RIGHT. ILMENITE IS FOUND AS A DETRITAL MINERAL TOGETHER WITH DIAMONDS IN CEMPAKA IN BORNEO (WHITE ET AL. 2016). IT IS ALSO FOUND IN THE URALS (LUKYANOVA ET AL. 1998).
BEST REGARDS
IOANNIS
ILMENITE HAS ALSO BEEN FOUND WITH DIAMONDS IN NW TASMANIA (BOTTRILL 1998).
BEST REGARDS
IOANNIS
Sedimentary diamond deposits are closely linked with a peculiar geotectonic-geological setting which is marked by three elements. The various placer deposits are in and around an ancient craton. The heavy mineral pathfinders depend on the primary types, the lamproite or kimberlite suites. Rock-forming minerals common to these two source- and host-rock lithologies of diamonds are used as pathfinder minerals in stream sediments and different placer types to find either profitable secondary or even primary diamond deposits:
Forsterite in association with pyrope and chromium diopside from heavy mineral accumulations, as a pathfinder to diamondiferous source rocks (Kopylova et al., 2000; Mafound, 2002). Titanite is a very widespread Ti-bearing mineral among the heavy minerals but in the stream sediments issues some sort of a "natural disclaimer" for diamonds to be abundant in the basic source rocks. Ultrabasic host rocks of diamonds used to concentrate Ti in heavy minerals like perovskite, titaniferous amphibole and phlogopite as well as ilmenite. In mixed-type placers diamonds, are found together with topaz, chrysoberyl, sapphire, ruby and emerald.
Further reading (open acess)
DILL, H.G. (2018) Gems and Placers—A Genetic Relationship Par Excellence.- Minerals 8/470: 1-43
HGD
DEAR HARALD
THANK YOU FOR YOUR DETAILED REPLY. I AGREE WITH MOST OF WHAT YOU WRITE. HOWEVER, I WANT TO ADD THAT MINOR DIAMOND DEPOSITS HAVE ALSO BEEN FOUND AWAY FROM CRATONIC OR PERICRATONIC AREAS. EXAMPLES ARE NSW, BORNEO, THE URALS, MYANMAR, THAILAND AND CALIFORNIA.
BEST REGARDS
IOANNIS
You are right. A compilation of diamand deposits you will find in the both "Chessboard articles....."
DILL, H.G. (2010) The “chessboard” classification scheme of mineral deposits: Mineralogy and geology from aluminum to zirconium.- Earth Science Reviews, 100: 1-420.
DILL, H.G. and WEBER, B. (2013) Gemstones and geosciences in space and time. Digital maps to the „Chessboard classification scheme of mineral deposits“.- Earth Science Reviews , 127: 262-299 plus supplementary material (99 maps showing gemstone deposits by country, geology and geomorphology) related to this article to be found on-line at http://dx.doi.org/10.1016/j.earscirev.2013.07.006.
HGD
Hi Ioannis Kamvisis
The minerals are garnet, chromite, ilmenite, clinopyroxene, olivine, and zircon.
Best Regards,
SHA
Hi Dr Ioannis Kamvisis . Indicator minerals for diamond include, in order of decreasing significance: garnet, chromite, ilmenite, clinopyroxene, olivine, and zircon. But the order of persistence in streams is zircon, ilmenite, chromite, garnet, chromian diopside, and olivine. See the link: http://earthsci.org/mineral/mindep/diamond/diamond.html
See the following RG link: Article minerals Diamond Exploration Potential of the Northern East ...
Also see the following link: https://en.m.wikipedia.org/wiki/Kimberlite
Kindly see also the following link: http://www.minsocam.org/msa/collectors_corner/arc/quartzdep.htm
There are so many machines nowadays, using that technology you can easily find out whether it's diamond, CZ, moissanite or Synthetic Diamond.
Aref and Adebowale thank you for your interesting answers.
Best regards
Ioannis
- Badges
- Science topic
- Similar topics
- Filing