There is only one way for you to study and determine the relationships between crystallization - deformation and subsequent genetic sequence: Please study the world class book by Ron H. Vernon (2004): "A practical guide to Rock Microstructure" published by Cambridge University Press. ISBN 0 521 89133 7 (paperback)

And please get additional advice from an experienced petrologist.

Please find in my publication list on ResearchGate as an example one of our publications detailing the relationship between crystallization and deformation of emerald and other minerals in thin section:

Multi-stage emerald formation during Pan-African regional metamorphism: The Zabara, Sikait, Umm Kabo deposits, South Eastern desert of Egypt.

By Günter Grundmann & Giulio Morteani (2007) In: Journal of African Earth Sciences 50 (2008) p. 168-187.

Best regards

Guenter Grundmann

Please refer to your email addressed to me.

I am not an expert on economic mineral deposits. But it is good you have placed your question on the Research Gate.

I can see you already have suggestions from Guenter Grundmann. I am sure others would follow. It would be better if you would provide some more information on the rock-types, and a couple of photomicrographs, preferably with name labels on the mineral grains

Wish you best,

Qasim Jan

Thanks Guenter Grundmann and M.Qasim for your kind suggestions

I strongly support Qasim's suggestion that we will discuss your individual cases on the basis of your thin section images here via ResearchGate. Please label the thin section images in detail so that we can analyze the relationships between crystallization and deformation. Please also pay attention to brittle and ductile deformation features visible in the thin sections.

Best wishes,

Guenter

I suggest you carefully check the unknown minerals under microscope. If possible, some advanced analyses (i.e., EMPA & SEMEDS) can be used to identify their ID. Their mineral sequence can be judged only based on some simple but clear relationship including across cutting, envelopment and replacement.

Mineral parageneses can be determined using textural relationships among individual grains. But as mentioned by you with REE bearing minerals like apatite, monazite, chevkinite, rinkite etc. are really difficult to identify under the polarizing microscope. However, the most identifiable among them is apatite which you can identify easily.

As mentioned by Zheng, you should go for systematic SEM study followed by EPMA. This will help to identify the REE-bearing phases as well as textural details involving them.

Thanks Yi Zheng and Aniket Chakarabarty for your nice suggestions

For the normal crystallization of major minerals you should know about solid solution and eutectic systems. The whole idea is which mineral is more stable under what PT conditions. There are some other minerals which forms during the melting reaction, these are called reaction product or periectic mineral. I will give you an example, during biotite dehydration reaction (crustal melting), which involves biotite plag and quartz as reactants and as a reaction product garnet and Kspar formes with some melt. How to identify this in thin section? Well, in thin section you will see reactant minerals in equilibrium with each others, their edges will be corroded embayed into each other with a thin film of glass and you will notice euhedral garnet and Kspar. Other example, in metamorphic rocks say in migmatites , during decompression melting garnet break down and cordierite forms and you can grow xenotime and monazite at the expense of garnet breakdown. For REE deposits, you should know the difference between magmatic and hydrothermal minerals. For example you can form zircon as magmatic or very late -stage precipitation out of hydrothermal solution. hydrothermal minerals may have very different texture then its magmatic counterpart for example zircon is spongy , porous and irregular shaped when precipitated from hydrothermal fluids.

In the nutshell, microstructures with a knowledge of mineral reactions and idea about which mineral should form at the expense of which other mineral(s) should provide useful information for the genesis of ore minerals. Other tools are petrogeochronology and microanalyses of the minerals to provide more robust constraints of mineral formation history and deformation.

www.matweb.com

Dear Amjad

It seems that your question has two parts.

The first part is about the identification, which can be resolved through careful examination under microscope or by using SEM-EDS or EPMA.

Regarding the sequence of mineral formation i.e., paragenesis, it can be resolved through textural studies.

Can you send this book ("A practical guide to Rock Microstructure" published by Cambridge University Press. ISBN 0 521 89133 7 (paperback) ) to me at this email-id.

[email protected]