This may be the author’s version of a work that was submitted/acceptedfor publication in the following source:

Lopez Toro, Andres & Frost, Ray(2015)Raman spectroscopy of pyrite in marble from Chillagoe, Queensland.Journal of Raman Spectroscopy, 46(10), pp. 1033-1036.

This file was downloaded from: https://eprints.qut.edu.au/84492/

c© Consult author(s) regarding copyright matters

This work is covered by copyright. Unless the document is being made available under aCreative Commons Licence, you must assume that re-use is limited to personal use andthat permission from the copyright owner must be obtained for all other uses. If the docu-ment is available under a Creative Commons License (or other specified license) then referto the Licence for details of permitted re-use. It is a condition of access that users recog-nise and abide by the legal requirements associated with these rights. If you believe thatthis work infringes copyright please provide details by email to qut.copyright@qut.edu.au

Notice: Please note that this document may not be the Version of Record(i.e. published version) of the work. Author manuscript versions (as Sub-mitted for peer review or as Accepted for publication after peer review) canbe identified by an absence of publisher branding and/or typeset appear-ance. If there is any doubt, please refer to the published source.

https://doi.org/10.1002/jrs.4699

1

Raman spectroscopy of pyrite in marble from Chillagoe, Queensland 1

2

Andrés López and Ray L. Frost 3

4

School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, 5

Queensland University of Technology, GPO Box 2434, Brisbane Queensland 4001, 6

Australia. 7

8

Abstract: 9

Samples of marble from Chillagoe, North Queensland have been analysed using scanning 10

electron microscopy with energy dispersive X-ray spectroscopy (EDS) and Raman 11

spectroscopy. Different types of marble were studied including soft white marble, hard white 12

marble and a black marble. In this work, we try to ascertain why the black marble has this 13

colour. Chemical analyses provide evidence for the presence of minerals other calcite in the 14

marble, including the pyrite mineral. Some of these chemical analyses correspond to pyrite 15

minerals in the black marble. The Raman spectra of these crystals were obtained and the 16

Raman spectrum corresponds to that of pyrite from the RRUFF data base. The combination 17

of SEM with EDS and Raman spectroscopy enables the characterisation of the mineral pyrite 18

in Chillagoe black marble. 19

20

Keywords: pyrite, marble, calcite, marcasite, Raman spectroscopy 21

22

23

Author for correspondence (r.frost@qut.edu.au) P +61 7 3138 2407 F: +61 7 3138 1804

2

Introduction 24

Extensive marble deposits occur in the mining town of Chillagoe, Atherton Tableland, 25

Queensland, Australia. Chillagoe is historically famous for the mining of gold, copper and 26

zinc. Extensive limestone caves exist in the Chillagoe-Mungana area. The geology of the 27

Chillagoe region is complex and diverse. Three types of marble are found including ‘soft’ 28

marble which is readily cut and ‘hard’ marble which is difficult to cut and destroys the 29

diamond cutting blades. It is suggested that presence of carbon exist in this type of marble 30

and is the cause of the hardness of the marble. Black marble is also found in the Chillagoe 31

marble deposits. For the soft marble, few distinct crystals are noted whereas in the hard 32

marble different types of crystals are readily observed. Different types of minerals are found 33

trapped in the Chillagoe marble. 34

35

Raman studies of pyrite have been undertaken for a wide range of purposes 1-4

including 36

extra-terrestrial materials, black shale, water rock interfaces, and nanomaterials. Studies of 37

pyrite oxidation and biological interactions have improved our knowledge on the stability of 38

pyrite 5-7

. Pyrite is often used for adsorption studies 8. Raman spectroscopy has been used to 39

analyses coals, black rocks and black clays 1, 9

. A diamorph of pyrite named marcasite is 40

common 10-12

. To the best of the authors’ knowledge there have been very few spectroscopic 41

studies of marble; let alone what minerals are found in marble. Marble is formed in the case 42

of the Chillagoe marble through the compression of corals (from ancient barrier reefs). So 43

whatever chemicals/ minerals are present in the corals will be retained in the marble. This 44

means that for example sand and silicates will be trapped in the marble. In this research, we 45

have undertaken a spectroscopic study of selected crystals in black marble. This work forms 46

part of an exploration of the reasons for the formation of the black marble. 47

48

3

There have been some Raman spectroscopic studies of geological materials 13, 14

used as 49

building materials. The study by Jehlicka et al. identified graphitic particles in marbles from 50

Bohemian Massif (Czech Republic) 15

. Raman spectroscopy has been used to study marble 51

statues of archaeological significance16

. Raman spectroscopy has proven very useful for the 52

study of minerals and their mineral structure, including silicate minerals17-21

. However, the 53

actual research on marble is very limited and as for the study of trapped minerals in the 54

marble, nothing exists. In this research, we have undertaken a SEM with EDX and Raman 55

spectroscopic study of pyrite found in Chillagoe marble. 56

57

Experimental 58

Samples description and preparation 59

A sample of hard shiny black marble was used for the analysis. Crystals were selected for 60

Raman spectroscopic analysis. Please see the graphical abstract for the placement of the 61

pyrite. 62

63

Raman microprobe spectroscopy 64

Samples of selected crystals in marble were placed on a polished metal surface on the stage 65

of an Olympus BHSM microscope, which is equipped with 10x, 20x, and 50x objectives. The 66

laser beam was focused on individual crystals. The microscope is part of a Renishaw 1000 67

Raman microscope system, which also includes a monochromator, a filter system and a CCD 68

detector (1024 pixels). The Raman spectra were excited by a Spectra-Physics model 127 He-69

Ne laser producing highly polarized light at 633 nm and collected at a nominal resolution of 2 70

cm-1

and a precision of ± 1 cm-1

in the range between 200 and 4000 cm-1

. Repeated 71

acquisitions on the crystals using the highest magnification (50x) were accumulated to 72

4

improve the signal to noise ratio of the spectra. Raman Spectra were calibrated using the 73

520.5 cm-1

line of a silicon wafer. 74

75

Spectral manipulation such as baseline correction/adjustment and smoothing were performed 76

using the Spectracalc software package GRAMS (Galactic Industries Corporation, NH, 77

USA). Band component analysis was undertaken using the Jandel ‘Peakfit’ software package 78

that enabled the type of fitting function to be selected and allows specific parameters to be 79

fixed or varied accordingly. Band fitting was done using a Lorentzian-Gaussian cross-product 80

function with the minimum number of component bands used for the fitting process. The 81

Gaussian-Lorentzian ratio was maintained at values greater than 0.7 and fitting was 82

undertaken until reproducible results were obtained with squared correlations of r2 greater 83

than 0.995. 84

85

Scanning electron microscopy (SEM) 86

Experiments and analyses involving electron microscopy were performed at QUT. Marble 87

crystals were coated with a 5nm layer of evaporated carbon. Secondary Electron and 88

Backscattering Electron images were obtained using a JEOL JSM-6360LV equipment. 89

Qualitative and semi-quantitative chemical analyses in the EDS mode were performed with a 90

ThermoNORAN spectrometer model Quest and were applied to support the mineral 91

characterization. 92

93

Results and discussion 94

95

Mineral characterization 96

5

The picture of the pyrite crystals are shown in Figure 1. A crystal of pyrite is shown in the 97

SEM image in Figure 2. The EDS spectrum is illustrated in Figure 3. This spectrum is typical 98

of the analyses of selected spots in the black marble. These spectra show the presence of 99

high sulphur containing minerals in the marble. The result of the analysis is reported in 100

Tables 1. The chemical analyses are indicative of pyrite FeS2. 101

102

Vibrational Spectroscopy 103

The Raman spectra over the 2100 to 100 cm-1

spectral range of selected crystals embedded in 104

the hard white marble are shown in Figure 4. This figure displays the recorded spectrum 105

together with the Raman spectrum of pyrite downloaded from the RRUFF data base. A strong 106

similarity is observed between the two spectra. These spectra may be subdivided into sections 107

depending upon the type of vibration being studied. The Raman spectra of the series of 108

pyrite and the RRUFF pyrite over the 500 to 300 cm-1

spectral range are reported in Figure 5. 109

Raman bands are observed in this spectrum at 342, 349, 377 and 428 cm-1

. These bands are 110

attributed to FeO stretching and lattice vibrations. Bands in the RRUFF spectrum are 111

observed at 332, 365 and 415 cm-1

. There is a small difference in the spectra from the black 112

marble and the RRUFF spectrum of pyrite. It is not known why there is a difference of about 113

10 cm-1

. In this work, we are analysing a small crystal in a calcite matrix as compared with a 114

bulk sample. The spectra in this work are also in agreement with those published by Mycroft 115

et al. 22

. Vogt et al. published the first phonon spectrum of pyrite 23

. Vogt et al. determined 116

the Raman band at 430 cm-1

which is in excellent agreement with our work. This band was 117

defined as the Tg mode. The Raman band at 377 cm-1

is assigned to the A1g mode in harmony 118

with the work of Vogt et al. This is the most intense band in the Raman spectrum of pyrite. 119

The Raman band at 342 cm-1

is defined as the Eg vibrational mode of pyrite. There is a 120

shoulder band at 349 cm-1

which is due to the Tg vibrational mode. There is good agreement 121

6

with our data and that published by Vogt et al. Turcotte et al. 24, 25

undertook studies of the 122

Raman spectrum of oxidised pyrite. 123

124

The Raman spectrum of pyrite over the 250 to 100 cm-1

spectral range is reported in Figure 6. 125

Raman bands are found in the pyrite from the Chillagoe marble at 111, 145 and 158 cm-1

. 126

Raman bands in the RRUFF Raman spectrum were not reported in this spectral region. These 127

bands are attributed to lattice modes. The positions of these Raman bands are in good 128

agreement with that published by Turcotte et al. These researchers studied the oxidation of 129

pyrite surfaces under different reduction potentials. The Raman spectrum of pyrite over the 130

1800 to 1400 cm-1

spectral range is reported in Figure 7. A Raman band is observed at 1601 131

cm-1

. The intensity of this Raman band is low. This band may be assigned to water bending 132

mode of adsorbed water. Transmission electron microscopy studies show that the studied 133

marble has a layered structure. It is proposed that this low concentration of water is due to the 134

entrapment of the water in the marble layers. 135

136

Conclusions 137

We have studied differing crystals in Chillagoe marble. Some crystals are found in the hard 138

white marble and some in black marble. Some crystals were found to be pyrite using SEM 139

with EDX and the chemistry of selected mineral crystals was determined. Raman bands are 140

observed in the spectrum of pyrite at 342, 349, 377 and 428 cm-1

. The Raman band at 377 141

cm-1

is assigned to the A1g mode; the Raman band at 342 cm-1

is defined as the Eg vibrational 142

mode of pyrite; a shoulder band at 349 cm-1

is assigned to the Tg vibrational mode. The 143

Raman spectrum of pyrite from this work corresponds excellently well with the Raman 144

spectrum of pyrite as determined with published papers. 145

146

7

Acknowledgements 147

Mr Vincent Boulter of the company Stone Export Australia (Chillagoe marble mines) is 148

thanked for the supply of the marble samples. The financial and infra-structure support of the 149

Discipline of Nanotechnology and Molecular Science, Science and Engineering Faculty of 150

the Queensland University of Technology, is gratefully acknowledged. The Australian 151

Research Council (ARC) is thanked for funding the instrumentation. 152

153

8

References 154

[1] V. Ciobota, W. Salama, P. Vargas Jentzsch, N. Tarcea, P. Roesch, A. El Kammar, R. 155

S. Morsy, J. Popp, Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy 156

2014, 118, 42-47. 157

[2] A. Courtin-Nomade, H. Bril, J.-M. Beny, M. Kunz, N. Tamura, American 158

Mineralogist 2010, 95, 582-591. 159

[3] R. Hochleitner, N. Tarcea, G. Simon, W. Kiefer, J. Popp, Journal of Raman 160

Spectroscopy 2004, 35, 515-518. 161

[4] A. K. Kleppe, A. P. Jephcoat, Mineralogical Magazine 2004, 68, 433-441. 162

[5] G. K. Parker, G. A. Hope, ECS Transactions 2010, 28, 39-50. 163

[6] C. Pisapia, B. Humbert, M. Chaussidon, F. Demoisson, C. Mustin, American 164

Mineralogist 2010, 95, 1730-1740. 165

[7] U. Villanueva, J. C. Raposo, K. Castro, A. de Diego, G. Arana, J. M. Madariaga, 166

Journal of Raman Spectroscopy 2008, 39, 1195-1203. 167

[8] M. Mullet, F. Demoisson, B. Humbert, L. J. Michot, D. Vantelon, Geochimica et 168

Cosmochimica Acta 2007, 71, 3257-3271. 169

[9] M. Hatipoglu, D. Ajo, Y. Kibici, D. Passeri, Neues Jahrbuch fuer Mineralogie, 170

Abhandlungen 2012, 189, 97-101. 171

[10] F. Huang, D.-m. Kou, Y.-z. Yao, P. Ni, J.-y. Ding, Guangpuxue Yu Guangpu Fenxi 172

2009, 29, 2112-2116. 173

[11] H. D. Lutz, B. Mueller, Physics and Chemistry of Minerals 1991, 18, 265-268. 174

[12] T. P. Mernagh, A. G. Trudu, Chemical Geology 1993, 103, 113-127. 175

[13] S. Bernard, O. Beyssac, K. Benzerara, Applied Spectroscopy 2008, 62, 1180-1188. 176

[14] J. Jehlicka, A. Stastna, R. Prikryl, Spectrochimica acta. Part A, Molecular and 177

biomolecular spectroscopy 2009, 73, 404-409. 178

[15] A. Stastna, J. Jehlicka, R. Prikryl, Geological Society Special Publication 2010, 333, 179

175-183. 180

[16] D. Miriello, I. Alfano, C. Miceli, S. A. Ruffolo, V. Pingitore, A. Bloise, D. Barca, C. 181

Apollaro, G. M. Crisci, A. Oliva, M. Lezzerini, F. Chirico, N. Mari, C. Murat, Applied 182

Physics A: Materials Science & Processing 2012, 106, 171-179. 183

[17] R. L. Frost, A. Lopez, F. L. Theiss, R. Scholz, A. W. Romano, Spectrochim. Acta, 184

Part A 2015, 135, 801-804. 185

[18] R. L. Frost, A. Lopez, F. L. Theiss, A. W. Romano, R. Scholz, Spectrochim. Acta, 186

Part A 2015, 134, 58-62. 187

[19] R. L. Frost, A. Lopez, F. L. Theiss, L. M. Graca, R. Scholz, Spectrochim. Acta, Part A 188

2015, 134, 53-57. 189

[20] R. L. Frost, A. Lopez, L. Wang, A. W. Romano, R. Scholz, Spectrochim. Acta, Part A 190

2014, Ahead of Print. 191

[21] R. L. Frost, A. Lopez, F. L. Theiss, A. W. Romano, R. Scholz, Spectrochim. Acta, 192

Part A 2014, 133, 521-525. 193

[22] J. R. Mycroft, G. M. Bancroft, N. S. McIntyre, J. W. Lorimer, I. R. Hill, Journal of 194

Electroanalytical Chemistry and Interfacial Electrochemistry 1990, 292, 139-152. 195

[23] H. Vogt, T. Chattopadhyay, H. J. Stolz, Journal of Physics and Chemistry of Solids 196

1983, 44, 869-873. 197

[24] S. B. Turcotte, R. E. Benner, A. M. Riley, J. Li, M. E. Wadsworth, D. Bodily, Applied 198

optics 1993, 32, 935-938. 199

[25] S. B. Turcotte, R. E. Benner, A. M. Riley, J. Li, M. E. Wadsworth, D. M. Bodily, 200

Journal of Electroanalytical Chemistry 1993, 347, 195-205. 201

202

9

203

204

10

List of Figures 205

206

207

Figure 1 Picture of pyrite in black marble 208

209

Figure 2 Picture of pyrite crystals in black marble 210

211

Figure 3 EDS analysis of pyrite 212

213

Figure 4 Raman spectrum of pyrite from the marble and the Raman spectrum of pyrite 214

downloaded from the RRUFF data base over the 2100 to 100 cm-1

spectral range 215

216

Figure 5 Raman spectrum of pyrite from the marble and the Raman spectrum of pyrite 217

downloaded from the RRUFF data base over the 500 to 300 cm-1

spectral range 218

219

Figure 6 Raman spectrum of pyrite from the marble and the Raman spectrum of pyrite 220

over the 250 to 100 cm-1

spectral range 221

222

Figure 7 Raman spectrum of pyrite from the marble over the 1800 to 1400 cm-1

spectral 223

range224

11

List of Tables 225

226

227

Table 1 Chemical analysis of a selected pyrite crystal using EDS 228

229

230

231

232

12

233

Element Line

Type

Apparent

Concentration

k Ratio Wt% Wt%

Sigma

Standard

Label

Factory

Standard

S K

series

50.93 0.39563 26.50 0.19 FeS2 Yes

Ca K

series

0.11 0.00092 0.06 0.02 Wollastonite Yes

Fe K

series

34.89 0.29895 21.11 0.17 Fe Yes

Total: 100.00

** Carbon is detected but is from the coating of the marble surfaces 234

235

Table 1 Chemical analysis of a pyrite crystal using EDS 236

237

238

13

239

240

Figure 1 241

242

243

14

244

245

Figure 2 246

247

248

15

249

250

Figure 3 251

252

253

16

254

Figure 4 255

256

257

258

259

260

261

17

262

263

Figure 5 264

265

266

267

268

18

269

270

Figure 6 271

272

273

274

19

275

276

Figure 7 277

278

279