Ahmed:

Kindly have a look at this link for helpful hints:

http://kashanu.ac.ir/Files/Content/C%20471M%20%E2%80%93%2001%20%20;QZQ3MU0_.pdf

Best

Syed

The gypsum content in a rock can be determined qualitatively and quantitatively with the Rietveld X-ray phase-analysis method.

Dear Dr. Salih,

XRD is a method to determine gypsum as well as the overall mineral assemblage, provided the minerals in question are present in significant amounts, and as far as the quantification of them is concerned you have got enough expertise on this method.

There is another  way useful for carbonate and sulfate minerals in thin section as well by differential staining using alizarin red S, Feigl´solution, titan yellow and Harris hematoxylin. It can be applied to aragonite, anhydrite, calcite, Mg calcite, dolomite, gypsum and magnesite. Gypsum and magnesite are the only ones at the end of the differential staining procedure which remain colorless after treatment with Harris' hematoxylin and take a purple tint after alizarin red S in 5 % NaOH. Even if you do not apply the full range of chemical compounds mentioned above it may be very much elucidating the texture and minerals in thin section, a fact relevant to draw any genetic conclusions.

I wish you much success

H.G.Dill

Use x-ray tomography ...and kindly see the link below

http://link.springer.com/article/10.1007%2FBF02465021

if you need to measure in the field, try portable XRF.  Instruments can be hired.

Portable XRF is probably not a good choice. For lighter elements such as Ca and S the detection chamber needs a vacuum in order for the instrument to read effectively. Portable vacuum pumps are available on some systems. Also be aware that the analytical results in portable XRF units are semi quantitative at best, unless your instrument is calibrated to the recurring texture of the rock you are trying to analyze. In addition the penetration depth of portable XRF units is extremely low, especially for lighter elements (e.g. Ca ~ 0.06mm). Which means that you are reading the composition of the very outside "skin" of your material.

XRD or thin section staining, as mentioned above, are probably your best methods.

There might be another way if the mineralogy of your host rock is simple. A rapid field density test can be used to break out the approximate fraction of gypsum in your rock. I have developed such a method and it was effectively used to determine the chemical composition of feldspars without the need for chemical analysis. (This was presented at the 2015 AIPG national meeting in Alaska). If you are interested, please contact me directly, and I am happy to help develop such a method for you, if your rock specimens are conducive to it.

Dear Friends:

Thank you so much for your help, I really appreciate.