Applied Mineralogy - Science topic

I wanted to determine the mineral depositional type at the area marked with green (Maran, Pahang - Central Belt of Peninsular Malaysia). The regional geology study shows the mineral deposition of this area is mainly in metasediment. There are 2 mines nearby the study area which are the RED and the PURPLE. I wonder is it possible to determine the mineral depositional type of my study area based on the nearby deposition type?

RED - Skarn type deposits copper mine (Au is very less)

PURPLE - VHMS type deposits gold mine

ORANGE - Normal fault (NW - SE trend) associate with serial of synclines (NE - SW trend)

Bit of background… Geotechnical engineering in mining focus on broader classification (RQD, Q, RMR etc). The makeup of rocks grouped in these classifications and other classes like lithology can vary significantly. For example, some data I’ve looked has a range of 40% iron content for an individual lithology. I would expect something like iron influence rock mass strength, an influence which would be masked if not lost, when relating the broader categories to excavation performance.

I am working to Determine Entrainment in Flotation of Minerals.

What are the problems of Determine Entrainment in Flotation of Minerals? And how do I fix them?

In general, what suggestions do you have for reducing the Entrainment in Flotation of Minerals?

Geometallurgical knowledge should be integrated into advanced process control and optimisation systems (APC) from a plant-wide to a mine-wide perspective. In order to understand the synergy between geometallurgical data (for instance mineral liberation, texture, mineralogy, geochemistry), plant Key Parameter Indicators (product particle size, recoveries, circulating loads, etc), and process control objectives in mineral processing operations, plant-and-material sampling and characterisation campaigns are necessary.

I know that this is a very difficult question, as the areas of application can vary greatly. However, if you want to operate low as well as high resolution (from a few millimeters to nanometers), need the highest possible beam current for analysis, but also very flexible with regard to large samples or non-conductive samples (low vacuum device), a whole series of devices or manufacturers fall out, as far as I know. If you don't want to constantly change pressure stage apertures, the only manufacturer I can think of at the moment is Zeiss.

I've put a photo of mineral that I do not know.

This mineral generally occurred near the contacts of chromite lenses on the surface of serpentine foliation like sheet Silicates. The color shows copper or bronze and metallic luster but it is a very strange formation such a mineral in a sheeted form especially in serpentinized dunite!

I would be grateful if anyone could provide me with the heat capacity coefficients of Ca[B3O4(OH)3] · H2O colemanite. Thanks.

My mafic meta-volcanic rocks can be devided into two groups. Group 1 rocks are distinct from Group 2 as displayed by their markedly higher concentrations of Fe₂O_3T (18.5-18.6 wt.%), TiO₂ (3.5 wt.%) and P₂O₅ (1-1.1 wt.%), lower MgO (5.1-5.2 wt.%) and lower silica contents (SiO₂ = 43.6%-44.3 wt.%). And the higher concentrations of the incompatible elements (i.e., Zr, Y, Nd, Sm, Nb and P) and lower concentrations of compatible elements (i.e., Cr and Ni) in Group1 are also distinct from Group 2. These features are similar to the Fe-Ti basalts which are characterized by iron- and titanium enrichment (FeO_T>12 wt.%, TiO₂>2 wt.% and FeO_T/MgO>1.75) but silica depletion (Sinton et al., 1983; Hunter and Sparks, 1987; Furnes et al., 1998; Jang et al., 2001; Harper, 2003; Qian et al., 2006). Because of the absence of Fe-Ti oxides phenocrysts, most researchers consider that the high concentrations of iron and titanium were not caused by the cumulus Fe-Ti oxides, and the Fe-Ti basalts are interpreted to be products of moderate to high degree of Fenner trend differentiation of basaltic magma at low oxygen fugacity (Jang et al., 2001; Xu et al., 2001; Qian et al., 2006). However, there are many Fe-Ti oxide phenocrysts in my samples, and no cumulate structures were observed in my samples. So it is hard to get the conclusion that they were formed from the cumulation process, I  want to konw which process can cause this geochemical features. 

Ladies and gentlemen, I have a favor to ask of you. If you've collected beautiful and back-corrected EBSD patterns of preferably non-cubic phases... could you send them to me along with the information about the projection center (pattern center + detector distance)? If this information is not available, it doesn't matter... It would also be nice to know the diffracting phase, but even that is not necessary if the pattern looks good. The resolution should not be lower than 400x300 pixels. In any case, it doesn't necessarily have to be high resolution patterns. The image format is irrelevant. I want use the patterns for tests regarding crystal lattice description (approximate lattice parameters and crystal symmetry). If I should use the patterns later in publications you can be sure that I will refer to you. Thanks in advance!

Is there any (real) advantage of a hexagonal grid used during orientation mapping? And if yes, is there any paper which discusses and proves this in comparison to a regular map? And why all other companies do not use this (inclusive other mapping software like ASTAR in TEM) ?

Invite a discussion on quantification of minerals in thin section and their correlation with XRD quantification using Rietveld Method for Quantitative Phase Analysis.

1. Different Approaches for quantification of minerals in thin section

2. Can we compare mineral quantification in thin sections with XRD quantification?

3. How to approach these techniques combined?

4. Or what is the relevance of other geo-chemical procedure such as Rittmann’s norm for stable mineral assemblage (or any other).

5. Accuracy of other mineral quantification techniques (when compare to thin section analyses) !

These photos taken at Sandstone layer . Please can somebody help me in the identification of these concentric and parralel laminations ? And which is the origin of this process ? NB : outcrops located on the coast influenced by marrine erosion.

Are there any specific minerals related to baddeleyite like the relationship between zircon and biotite minerals?

These are thin-section photomicrograp of Continental Carbonate rocks ( XPL and PPL). Can somebody help me in the identification of minerals marked by red arrows ?

Thank you very much in advance.

15 years after the introduction of CCD-based EBSD detectors a new camera technology enters the EBSD world. It is hard to believe, the formerly demonised CMOS chips are now the saviours of the EBSD market. In contradiction to all prevously made statements CMOS are now not only faster but also more sensitive and less noisy. Well, companies are (primarily) not founded to make scientists happy. They need to sell in order to survive (or make their shareholders happy), and if the market does not increase as expected a new technology is very welcome to increase the business ono this way.

In fact, I believe that the spec sheets of the new detectors are credible, but how the detectors really work in practice? Are there some users which have direct comparisons? How profitable is the change if one considers the comparatively huge price?

The backscattering of electrons obviously happens with the core of the atoms or ions. If it is related to the mass I would expect an impact of protons and neutrons. If it is an impact of the charge (quite unlikely since plus and minus should attract each other) it should be proportional to the the protons only (i.e. Z, the atomic or periodic number). Nevertheless, it is not a single event since we have a practically unlimited number of interactions which should be related to the number of atoms (cores). This would bring the packing or mass density (or in first approximation the materials density) into the business. This from my present point of view very logical conclusion is in strict contradiction to experimental observations: comparing lead (density around 10g/cm³) and gold (density around 20g/cm³ ), lead has a higher backscatter coefficient. Does anybody have an idea, why the backscatter coefficient scales with Z and not with the density...or something else like a proton-density since the mass density also considers the neutrons?

We measured a microstructure of hydrothermal Au by EBSD and EDS which contains locally a small amount of Ag. The pure gold areas are not separated as grains but obviously linked to large angle grain boundaries only, see the attached image. Has anybody seen a similar microstructure or can explain the occurence of (secondary) Au?

We've just analysed a microstructure of a cubic closed-packed (fcc) material. As visible from the color-coded IPF map (Y parallel to the long axis of the grains) the aspect ratio of the grains is quite high so that I would expect a fiber texture. Surprisingly, the related pole figures do not show a very pronounced texture. I already considered a half width of 10° in order to get something like a smeared pole distribution. There is certainly no "homogeneous" distribution (MUD=5) but the maxima are more related to a few major texture components than to a fibre. To me it seems that the number of grains is too small for a description of the really existing texture.

Has anybody observed already a similar phenomenon? Grains with a high aspect ratio but no "matching" texture? What could be the reason?

The materials has not been heat-treated!

I would like to know how should I determine the price of the possible monazite sand? I do have an ICP-Mass test result which indicates elements present (attachment). For a feasibility study I need to determine the price for the raw sand but I do not know any guidelines or references to do so.

Suggestions are more than welcome.

Usually the chemistry (Elemental composition) by Rietveld results is not correlating with Chemical assays (XRF or Whole Rock Analysis). When I refine my diffractogram, using scale refining, i'm matching  more or less the Rietveld  chemistry, however to hold the visual match and good GOF I refine (constrained) the occupancies. Is it right?  

I did check the ammonium containg two different samples such as 2:1 clay mineral and jarosite in XRD, FTIR, EA/IRMS analysis .

and I have a plan to SEM analysis for 2:1 clay mineral  (i.c. Montmorillonite, nontrite, saponite etc..) and jarosite. 

How to distinguish between above the  two samples on the SEM images, for mineral structure or texture?  

And also, how to estimate that dioctahedral or trioctahedral type for 2:1 clay mineral on TEM analysis? I don't know whether it is possible or not.

Of course, i confrimed at 060 peak in XRD analysis..

anybody, teach me above my current issues..

Using Ti for the calculation, various geochemical process might add or subtract Ti in zircons, as inclusions, overgrowths, mantled e.t.c. Ti-rich mineral or fluids can be incorporated, thus does give any meaning on the crystallization history. What is the opinion of experts in this field.

when I study the  evolution of barck-arc basin magma, we find some melt inclusions in plagioclase have much higher silca than matrix glass from andesite,why?

I have been working on research about gold characterization so, I got a few questions regarding on my research that I curious to know such as; 

i) Is there any standard range value for LOI if the gold was characterised as carbonaceous gold ore?

ii)What is standard temperature normally used for LOI test on gold ore sample?  

iii) Let say if the Carbon element was detected on every spot of the gold rock sample in SEM/EDX analysis with the high percentage, does it mean the gold sample belonged to carbonaceous gold ore based on the SEM/EDX result?

Thanks.

rock compositions of sampling area are mainly clay silt, sandstone, conglomerate etc.  sample depths : 50-650cm,  yellowish brown color.

i want to know peak position  (2θ,  near 9º ?, 12-13º ?, 15º ?, 17-18º?   , meybe 24-28º are quartz? frankly speaking, i'm not sure that .. 

 

just, i confirmed nitrogen contents all samples by EA/IRMASS analysis.  so, i suggest that the existence of K-bearing minerals such mica group or smectite group.

I follow the Niggli's diagrams for the amphibloite rocks which I am working on.

Could you help me how the Niggli ratio should be calculated?

Please let me know in details as well as an example.

Thanks.

I'm trying to float oxidized zinc ores but the lead oxide (cerussite) was floated with the concentrate of zinc !!!

It is well known that pyrite shows striations along <001>. Although cubic but according to the point group symmetry m-3 the striation is commonly only visible along one of the <001> on {100} or {210}. Invisible on {100} but on {210} is a change of striation which is called positive or negative. The positive is assumed to be || <001>, the negative is perpendicular to <001>, i.e., ||<-120>.

Is it possible that in the last case {210} is actually {120} and the striation is always || <001>? Is there any experimental confirmation known which shows that the formed dodecahedron plane is definitely the {210} or not perhaps in rare cases {120}?

I'm looking at altered volcanic tuffs hosting Cu-Zn-Co-Mn manto mineralization at the Boleo deposit, Baja California Sur, Mexico.  We are trying to find evidence of hot spring activity.  Silica deposits are very fine grained and have not yielded fluid inclusions yet, but we have what appears to be  carbonate-silica sinters with tubes lined with a coat of Fe-saponite (tentatively identified).  Other minerals present include gypsum, dolomite, Mn oxides, strontianite, and a few others.

Is there any free software that can calculate tetrade effect, Eu, and Ce anomalies of rare elements?

Hey guys,do you know any useful methods to define a adularia whitout obvious rhombic-like shapes? Raman or some other agents?

Antigorite, Lizardite and Chrysotile are serpentine minerals which have the same chemical composition but they are formed separately, so what are the conditions that control that?

I am working on Columbite-Tantalite-Cassiterite deposit in West Africa. We have intersected numerous high grade Columbite and Tantalite mineralisation in our trenches on hill top grading over 1Kg/m3 with numerous +25mm grains (largest grain weighing 1.35 Kg). However when our trenches reaches the weathered pegmatite which we expect is source rock we do not find mineral grains. Is there any geological explanation for this? 

How reliable is a determination of lattice parameters using a single electron backscatter diffraction pattern? Who determines lattice parameters in order to discover/identify a local phase, e.g. precipitates in a matrix? Is there any specific software available?

Thanks! 

I am trying to find a safer and cheaper way to separate heavy minerals. I heard that bromoform is highly toxic, SPT or LST are too expensive for sole researcher from Africa, is there another method I can try.

thank you 

Q4. In below Pictures can Any one Identify The Mineral?

This is from quartzite sample.

it lookslike chloritoid but with bright interference colours

Ten 10 of the samples analyzed have values that range from 0.45 - 0.61 while 3 samples range from 0.51 - 0.59. I assume the samples analyzed are more of hydrogen - poor vitrinite A. I need more enlightenment on the subject.

I obtained a chemical composition of a plagioclase grain in weight percentage using SEM-EDS technique. The recalculated chemical formula of the grain is as follows using an MSExcel worksheet based programme.

Na0.5Ca0.2Al1.1Si2.3O8

Here the charge balance is problematic. What could I have possibly missed here?

Thanks in advance 

The mineral, picroilmenite, which means ilmenite containing Mg. I want to ask whether this mineral could indicate the pressure conditions? Thanks a lot!

Hello

i am collecting published lead isotope data for mineral deposits( mainly copper, zinc, lead,and tin) in the  Urals, Kazkahstan and Siberia(Altai, Minusinsk , Tuva and Baikal). Does anyone know which journals or books I should look for? Either  Enlgish or Russian publications are okay. 

Can someone suggest  any introduction books for tectonics and metallogenic provinces in Russia?

many thanks,

Gary

Little info:

-These grains have been tested in the SEM with the EDAX attachment and the data reads as the following (on average):

20 - 25 wt. % Na, 20 wt. % Zn, 20 wt. % S, 5 wt. % Au

The rest of the total 100% is oxygen and carbon with trace elements filling up the rest.

This is an incredibly high amount of gold and I'm pretty sure that it is some kind of ZnS sphalerite, but the amount of Na is seriously throwing me off.

-p.s. the grains I'm talking about are the lighter grays with inclusions of some metal I'm unsure of.

Hi, somebody had written about methamorphism of orto piroxenites?

Thanks alot in advance.

Greetings

Marco

I have the cif file of a certain crystal,I was wondering how I can do AE or BFDH calculation to get the morphology,is there a free software to do these sort of calculation?

Help me Transfer measured values of gamma activity of rocks from units API to system units SI, please

I'm looking for stability fields for variscite, wavellite, kidwellite and millisite, function of PO4, Al, Ca, Na and K availability.

Dear all,

Recently I got a Cenozoic picrite sample containing a lot of olivine grains (Fig. 1).

The major element result of the picrite is:

SiO2 42.24

TiO2 1.50

Al2O3 10.02

Fe2O3T 11.50

MnO 0.18

MgO 19.51

CaO 8.64

Na2O 2.39

K2O 0.74

P2O5 0.61

LOI 2.04

Total 99.37

The whole rock composition represents a liquid + accumulated olivine.

The trace element result shows an OIB-type pattern, with significant depletion of K, Zr, Hf, Ti and Y, likely indicating a mantle source of carbonated peridotite (Fig. 2).

The olivine in the picrite are typical igneous origin. They have melt inclusions and high CaO content, and a very narrow rim with lower Fo value and higher CaO content (Fig. 3). The composition of the olivines in the picrite are homogeneous:

Na2O 0

NiO 0.229

K2O 0

SiO2 40.12

FeO 11.96

CaO 0.226

Al2O3 0.056

MnO 0.187

MgO 47.269

Cr2O3 0.04

TiO2 0.06

In order to calculate the mantle potential temperature and the depth of partial melting, I tried the software PRIMELT2.xls. The mantle potential temperature is ~1500 celsius degree. However, the calculated primary melt is balanced with Fo 91 olivine but not the measured olivine (Fo = 88)...

The samples of U-sandstones/siltstones consist of quartz and very fine grained matrix. The huge amount of quartz (60-90%) complicates a more detailed determination of ore-phases. These are bonded to the fine-grained matrix, which contains clay minerals and ore-phases (smaller than 1 μm). One of the possibilities is to remove quartz and thus to concentrate the uranium and uranium-bearing minerals. Many thanks for help!

In the paper "The key role of mica during igneous concentration of tantalum" contributed by Stepanov et al., (2014), they summarized that "crystallization of 99.9 % of melts precipitating 10 % of muscovite might increase Ta/Nb by a factor of 8 and concentrate Ta to 760 ppm in the residual melt. I am confused how they get this conclusion and how they calculate that. I used the equation for Rayleigh crystallization but failed to get the same value.

I've noticed this visual attribute is a known indication of oxidised ASS. But I can't find any information on the geochemical nature of the material.

From the academics I've spoken to, they hazard a guess at it being an extremely disordered Fe-oxyhydroxide. Another suggestion included organics as a component due to the shiny-ness of the film.

Just wondering what other thought?

XRD analysis was performed on a sample yielding a mineralogy of vivianite, gypsum (both of these appearing in several other samples), then pyrite, ankerite and Al, which were unique to this sample. However there was a very high noise level on the pattern trace for this sample, so the reliability of these results are in question.

I've attached a pic. any help would be greatly appreciated as I'm so very curious.

thanks heaps

See the mass spectrum and the SEM image below.

Thanks for your help.

A dacitic rock sampled from a dike has a very fine grained, reddish mineral that gives brown color to this rock. This mineral is almost everywhere in the matrix of the rock. What could it be? An alteration product? 

Photos and photomicrographs are attached.

Thanks in advance!

Jovid.

we have gold in pyrite ore, we extract this gold by flotation, but some time we have with our ore kaolinite clay which interfere with gold in flotation and give and give us bad gold recovery.

The study of ore mineralization is difficult for the size of mineral phases (in μm), gel nature of components etc. Application of traditional geological instruments (EPMA, SEM, XRD) is often limited due to the low-grade ore, particle size or colloidal nature of uranium and uranium-bearing phases.

I have been observing a metamorphic rock that contain Almandine garnet using SEM-EDS. The presence of garnets is confirmed by the very rock's XRD patterns (both Pyrope and Almandine are present).

Element analysis (SEM-EDS) of various points on Almandine/pyrope shows the following general chemical composition in wt%

Na - 0 - 1%      K - 0 - 1 %  Al - 17-19%

Mg - 4 -7 %     Si - 25 - 30%

Ca - 4 -1 %     (Total)Fe - 30 - 35 %

Strangely, Sulphur is there ranging 0 to 2%

Is it natural to have Sulphur in garnet? and are Na, K, Mg and Ca inter exchanging with each other?

Additional Info (XRF analysis (FP method) shows S element about 1.6 wt%. but XRD does not show any peak for possible Sulphur bearing minerals such as  pyrite or gypsum. Still the rock samples have strong sulphur smell).

Thank you in advance

Is it possible to have Fe2O3 in Sillimanite?   I observed (under SEI) a sillimanite looking grain (in a metamorphic rock sample)  with characteristic cross fractures in my SEM-EDS studies. But several points along the very same grain show the following composition;

Alumina - 58 - 61 wt%

Silica - 35-38 wt%

FeO+Fe2O3 - 3 -5 wt%

Is this gain is sillimanite or something else. Is it possible Alumina to be replaced with Fe2O3?

Thanks in Advance!

I have to work with major and trace element data of mafic dyke samples from the  different swarms of Eastern Dharwar Craton.Although several published literature used the correspondence analysis method for their data, however I am concerned about the procedure. How it will be useful in comparison to the other variation diagram ?

I'm studying augitic pyroxenes from a back arc volcano, included in basalts. Till now I find all those pyroxenes quite similar in terms of major elements, but different sized crystals and along one crystal (from core to rim) the composition in minor elements (such as Ti, Al and Cr) vary significantly, being Cr the one varying from 0.1 to 1.2%. 

I find Ti and Al (and also Na) with fitting profiles, but Cr seems not to be related with all the rest. Does anyone have a clue processes leading Cr partitioning? fO₂ may be an candidate but I'm not sure ti may be the main reason.

During some routine pegmatite mineralogy we came across an unknown mineral in association with the very rare-mineral 'fluorcalciomicrolite'. We no longer have the grab sample from which the thin section was taken but still have the thin section and have had the opportunity to analyse it quantitatively, along with some element mapping.

The results confirm that our mineral is possibly unique or possibly a second world occurrence of the recently discovered 'peterandresenite' but with high concentrations of Ta, presumably substituting for the Nb. The question is, what additional work can be done to confirm or publish the results bearing in mind all that we have is a normal 30 micron thin section of the mineral in question? 

The correct identification of phases is a fundamental information for a meaningful characterization of a microstructure by EBSD, especially when the phase is of minor fraction and cannot be discovered by other, more sensitive  techniques like XRD.

How accurate lattice parameters need to be known if the phase is assumed to be identified properly? Is there any important application where it would be beneficial to know the used phase better than now?  

I would like to compare my analysis from the tweefontein area (South Africa) to other localities in order to better understand the formation processes.

Could anyone please let me know that max and min value of CaO/Al2O3 and Na2O/Al2O3 in plagioclase or in feldspar?

Thanks in advance

Tiger's eye consists of quartz crystals. As far as I know it has been transformed from riebeckite (asbestos) which still is the reason for the fiber-like structure of tiger's eye. Does anybody know how riebeckite is transforming into quartz? The grains obviously still remain, and both structures contain of SiO₄ tetrahedra (differently linked). 

recently, i received a green stone, and grounded it to perform XRD analysis, but without the composition information, i cannot make sure what phases it contains. is there any one who are warm-hearted to help me?

How can I find research papers or reports about "preparing the metallogenetic maps". Their standards and coverages?... Thanks.

Can somebody explain the formation of the reaction rim around these Quartz  derived from felsic igneous rocks occurring in Lower Cretaceous Urgonian-type lms?

Photos are taken with crossed nicols.

I am going to establish the pH of montmorillonite or bentonite dispersion at a previously set ionic strength (e.g., 5 mM NaClO₄) in order to study their aggregation subsequently over a period of several days. However, once I adjust the pH with 0.1 M HCl/NaOH, immediately afterwards it changes, e.g., from 8 to 7.5 within a few minutes in the case of montmorillonite, or from 9, 7 and 5 to 8.3, 7.6, and 6.4, respectively, within several days in the case of bentonite.

The use of standard buffer solutions may not be appropriate for these experiments, since the buffer solution can change the surface characteristics of colloids as well as having no significance to the real environment.

I would highly appreciate it if somebody could suggest a simple and fast way to maintain the pH for this kind of experiment. 

How can I differentiate igneous and metamorphic zircon base on the REE of zircon for example Eu, CE anomaly or enrichment of HREE

can anyone suggest references?

Hello,

I am working in a project with GIN methodology, I have some question about considerations.

1. In order to obtain a seal criteria of the injection what is the consumption criteria? I read in Lunardi documents and he explain that the criteria will be Pmax, PvsV or flow. What will be the flow criteria or consumption of bags of cement?

2. If I change my GIN number so drastically in my construction stage, I need to evaluate the initial injections that I did or re inject?

Spectroscopic equipment of which company would you recommend for research and why?

In order to concretize the question...

Investigated objects are heterogeneous in structure and color of the surface (e.g., mineral objects, food items).

The task is to search for selective features

The spectral range of research - from UV to NIR.

Thanks for your opinion