Textural and Chemical Characters of Lean Grade Placer Monazite of Bramhagiri Coast, Odisha, India

Round 1

Reviewer 1 Report

This paper deals with the textural, chemical, and mineralogical characteristics of a placer sand containing monazite, an important REE ore mineral. This is an important and topical issue as it deals with deposits of critical raw materials (REE). However, several critical issues are present, especially in the mode of quantitative mineralogical analysis.

·        Introduction: it would be helpful to include some literature references on the mineral chemistry of monazite. It would be helpful to briefly state the general characteristics of a placer deposit (types, genetic aspects, mineral characteristics, etc.).

·        Materials and methods: what do you mean by “standard sampling methods”? At least specify references, sampling depth, mass of samples, mode of quartering, etc. State the analytical instrumentation used (manufacturers and models of SEM-EDS, XRD, Raman, optical microscopy) and analytical conditions.

·        By what analytical technique, under what instrumental conditions, and with what software was the quantitative mineralogical composition determined? Even to the second decimal place?

·        How was the monazite concentration determined?

·        How was the chemical composition of monazite determined in EDS? In standardless mode or using standards? With what margin of uncertainty?

·        How did you obtain structural data from XRD analysis? Under what experimental conditions, with what instrument, and with what data processing? With what usefulness?

·        Figure 1: too small, unreadable. Possibly make two separate figures, one for geographic location, the other for geology.

·        Figure 6: Fix the figure, character, and alignment. Possibly redo it as it is unclear.

·        Figure 12: Low quality, unreadable, and with too small a graphic scale.

·        Figure 15: Why are analyses reported in elements instead of oxides (as in the introduction)?

·        Figure 16, 17 and 18: somewhat questionable correlations. What is the usefulness of these correlations?

·        Figure 19:

·        Table 2: elements with low concentrations should be given in ppm (and obviously should be specified). The table as it stands is very unreadable.

·        Table 3: Is it EDS microanalysis? Standardless or with standards? Why is the sum of the elements not indicated? How do you indicate concentrations of U and Th to the third decimal place?

·        Conclusions: rather trivial conclusions, and especially based on analytical data of unclear origin and accuracy.

·        References: They need to be implemented, especially in the mineralogical and analytical part.

·        Insert superscripts and subscripts correctly in mineral formulas, e.g. lines 54-56-57-58-78-79-258-259-283-284.

·        Use acronyms correctly: for example, heavy rare earths are sometimes denoted (incorrectly) by HRE, others (correctly by HREE).

The English turns out to be cumbersome and not very fluent; a thorough revision by a native speaker is needed.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Line 2, Title: You need to remove @Mineralogical@ from the title because you here investigate a selected heavy mineral and not the bulk placer. If your title is correct, isn't it strange to mention about mineralogy of monazite, which is a mineral by its own?.

Line 13, Abstract: Are the contents of P and Ca attributed to the monazite only?. What about apatite?.

Line 15, Abstract: This sentence needs to be re-phrased to include a size range. Therefore, it is better to correct it to: "Size of investigated monazite is commonly below the range 150-90 μm.

Lines 17-18, Abstract: Did you build up the account on the source (provenance) of monazite to be derived from khondalite on a geochemical basis only?. Don't you have other country rocks, e.g. felsic rocks, in the hinterland that can feed the coastal dunes with monazite?.

Line 33, introduction: It is wrong to say that monazite is a phosphate-bearing mineral. In order to correct this, you need to say that monazite is a phosphate mineral or a mineral that bears phosphorous as an essential component in PO4 coordination.

Lines 35-40, Introduction: Font problem exists. Try to unify the font size for all the chemical formulae of minerals.

Lines 85-86: You give here the exact title of your manuscript as the aims of study at the closure of the introduction section as follows: “The present paper is aimed to study the Textural, Mineralogical and Chemical Characters of Lean Grade Placer Monazite of Bramhagiri Coast, Odisha, India”. You need to rephrase this and present crystal-clear aims to attract the reader to continue reading.

Line 95, Fig. 1: This caption is extremely small and needs to be re-edited considering size. If you use a Landsate imagery, you need to report type and date at least, in addition to scale.

Line 95, Fig. 1: It is too small especially the geological map. You need to enhance the three shots and make them ready for reproduction. For example, rock types in the legend of the geological map is not readable.

Line 100, Fig. 2: For this figure, first you need to give the caption below the picture in a different format, presumably WORD before conversion to the pdf. Second, tone of this mosaiced picture is not uniform and third you need to remove the sky blue background.

Line 113, Fig. 3: In this figure, you still have the problem of editing. Also, you need to re-edit some numbers in the circles and explain what is this number?!.

Line 114, Fig. 114: It is strange to include garnet among the magnetic minerals in your each sand dune.

Line 144, Fig. 6: This figure is badly prepared and it seems the authors just matched two separate charts incorrectly. Please re-edit and make it in a good quality for publication in an international journal like "Minerals". The figure shows very bad editing and presentation of scientific datasets.

Line 145, Fig. 7: There is the issue of bad editing again. How come you insert the figure caption at the top of figure?. Also, when you abbreviate something, you need to report it in full in the caption. For example, in this figure, you include THM as Total Heavy Minerals. It is strange that there is no monazite in front, central and back parts of the sand dune. You need to explain the reason, which is unclear in the text.

Lines 149-150: This is very confusing all over the text. Here you report minerals by count and as percentage and not by weight. Even if you mean with respect to the volume of the bulk sample, you need to show this straightforward.

Lines 155 and 162: You can only say heavy minerals but when you specify a mineral name, e.g. zircon or ilmenite, you do not need to write zircon mineral or ilmente mineral. You need to consider this for the entire text.

Lines 177-178: Not correctly phrased. You need to re-phrase and make your information clear for the reader. Although I am a professional mineralogist for over 30 years, I am confused with what you say here.

Lines 184-185: It is contradiction and you should report what you mean distinctly. Here you mean abundance of monazite then no need to use the term "concentration".

Line 188, Fig. 11: You need to distinguish this figure into (a) and (b). Then in (a), the Y-axis is not wt% it is percentage as an expression of mineral abundance.

Line 195-196: It is wrong to mention this and monazite is a particle by its own in a detrital deposit, a place here.

Line 213, Table 1: Abbreviations in this table captions must be given.

Line 229, Fig. 12: Vey badly edited. Resolution is bad so the mineral abbreviation is unreadable.

Lines 219-228, Mineralogical Characterization: Weak microscopic description. Try to improve taking in consideration that you give the biggest attention to morphology and possible textures and not to describe classical optical properties of minerals.

Line 243, Fig. 15: Resolution is very bad. Also, remove K, L and M for the EDX elemental measurements. Also, you need to give the composition in the form of oxides wt% and not as element wt%.

Line 268, Table 3: This is very wrong. Please use oxide and no need for % because the concentrations are given in a separate column. Also, you need to subscript. Please apply for the entire text.

Line 296, Fig. 16: Keep the regression value only for the correlation plots. Remove the connecting lines for the plot points. Same are in Figs 17 and 18.

Line 313, Table 5: It is strange to use ppm for oxide contents even for uncommon oxides.

Line 354, Fig. 20: In a research paper, you do not need to report basic information about mineral structure from a textbook unless you modify the structure and give refinement in terms for lattice structure.

Lines 357 to 393, Conclusions: The authors tell about industrial applications of the investigated placer monazite without specifying them. This needs more care and enhancement.

Please re-edit the reference according to style of the journal and instructions for authors.

Use the attached annotated pdf for the revision.

Comments for author File: Comments.pdf

Topic is suitable for “Minerals” but the authors need to revise their manuscript carefully and apply the main concerns of scientific writing. After major revision, I recommend the acceptance.

English needs polishing and editing of tables and figures need ultimate care.

Annotated pdf is attached in case the author will need for the major revision.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Dear authors, thank you for the corrections and additions, still remain to fix the layout and some minor corrections:

-        Figure 1: It would be helpful to include a graphic scale in both the left and right images

-        Table 2: insert subscripts correctly in the first line

Table 6: insert subscripts correctly in the first column

Minor editing of language required

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Thank you for the revised version. I hope you extend your work in the future on placer monazite and use EMPA instead of EDAX. This will give much better and precise information of broad scientific merit on the international scale.

Acceptable level of English even though in need of very fine polishing.

Author Response

Please see the attachment.

Author Response File: Author Response.doc