I have uploaded a powerpoint filled with SEM images of rocks:
RH01, RH02, RH011 are conglomerates. - Waitemata Group
RH03-5 are unconsolidated sandstones. - Tauranga Group
RH06-9 sandstone/mudstone from turbidites. Waitemata Group
RH12-13 siltstone. Waitemata Group
The rocks originate from Auckland, New Zealand.
I am struggling to define what they are, the names in red are potential minerals I believe they could be. Any help would be appreciated and I understand no one will be able to define all of them, but even if someone could look at a few it would really help me out. Also, I understand answers cannot be given with 100% certainty.
I have conducted XRD and generally, the results were Quartz, Anorthite, Albite, Orthoclase, heulandite, Mordenite and Oligoclase. I am looking for erionite mainly.
However, a lot of the images are of minerals growing within pore spaces that weren't forming the bulk of the sample.
If anyone would be able to help me out I would really appreciate it.
I gave a very quick look and I am surprised to see a peak of Fe, and Ti for zeolites. I don't know if you have checked if all those elements are really there or some of them may be Kb of other elements. Some of the habits of the minerals you show remember zeolite minerals like chabazite, but the spectra do not fit. In any case you may be looking at a mix of phases (e.g. zeolite + epidote group minerals, maybe also some TiO2). You may use RAMAN to help find out what exactly the phases you are looking at are. I am afraid SEM is not enough to tell one zeolite from another.
Dear Mrs. Patel,
it is a huge pile of work for a person to go through the SEM scans and the images showing the crystal morphology. I am not familiar with the local geological setting but all what I can see is as I skim the mineral association that of a siliciclastic sediment (cannot say anything about the grain size, whether it is a conglomerate or arenite) with a strong volcaniclastic imput probably from a basic volcanic rock. As far as the zeolites are concerned see the following papers with micrographs showing the crystal morphology and mineralogical association:
DILL, H.G., FUESSL, M. and BOTZ, R. (2007) Mineralogy and (economic) geology of zeolite-carbonate mineralization in basic igneous rocks of the Troodos Complex, Cyprus.- Neues Jahrbuch für Mineralogie Abhandlungen, 183: 251-268.
DILL, H.G., KAUFHOLD, S., LINDENMAIER, F., DOHRMANN, R., LUDWIG, R. and BOTZ, R. (2012) Joint clay-heavy-light mineral analysis: A tool to investigate the hydrographic- hydraulic regime of the Late Cenozoic deltaic inland fans under changing climatic conditions (Cuvelai-Etosha Basin, Namibia).- International Journal of Earth Sciences, 102: 265-304.
DILL, H.G., TECHMER, A., BOTZ, R., DOHRMANN, R. and KAUFHOLD, S. (2012) Hypogene and supergene alteration of the zeolite-bearing pyroclastic deposits at Tell Rimah, Jordan, and rift-related processes along the Dead-Sea-Transform Fault System during the Quaternary.- Journal of Volcanology and Geothermal Research, 239-240: 49-68.
DILL, H.G., KAUFHOLD, S. and HELVACI, C. (2015) The physical-chemical regime of argillaceous interseam sediments in the Emet borate district, Turkey: A transition from non-metallic volcano-sedimentary to metallic epithermal deposits.- Journal of Geochemical Exploration 156: 44-60.
All are available for download on the Researchgate server.
Please consult for zeolites textbooks like Gottardi and Galli, 1985; Gottardi, 1989; Tschernich, 1992; Coombs et al., 1997.
For zeolites it is not wise to trust in and use only one method. Make use of thin sections, SEM EDX/WDX, Micro-Raman, XRD single X and your eye-sight under the stereomicroscope for XX morphological studies (see for this approach especially Tschernich 1992).
I wish you much success
H.G.Dill
Hi Samuele Papeschi I was also surprised to see Ti, but for the Fe I think it comes from weathering. And thank you for your response.
Hi Harald G. Dill Thank you for linking the research articles, they were very helpful. Especially as I have also done FTIR on some of the samples and was looking for further information on IR spectroscopy too.
For X-Ray diffraction, which sampling method you used? What is the scan range? Is it slow scan or ? If you used zero field sampling with slow scan at more, surely you may get Erionite. And one more, please use the Xpert High Score software manually select the element to match the minerals. Best wishes
Hi Vijay Anand Sundarrajan I did scan from 2-60 2theta. I managed to use XRD and figure out which minerals I l was looking at, thank you.
Dear Mrs. Patel,
the crystal form and cleavage (010) of sample RH02b are common to heulandite.
see: https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Heulandit-Ca
Kristall Nr. H090bb
I did not calculate the formula. C from sputtering?
Best wishes
Heinz-Peter Koch