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Pyrrhotite
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<h2 id="structure">Structure</h2> <p>Pyrrhotite exists as a number of <a href="/facts/Polytypes/bu2tqsB9">polytypes</a> of <a href="/facts/Hexagonal_crystal_system/sSSok8wo">hexagonal</a> or <a href="/facts/Monoclinic/5PCwXvzX">monoclinic</a> <a href="/facts/Crystal_symmetry/bJ4bCeHd">crystal symmetry</a>; several polytypes often occur within the same specimen. Their structure is based on the <a href="/facts/Nickel_arsenide/fbXdeD92">NiAs</a> <a href="/facts/Unit_cell/znygJqdx">unit cell</a>. As such, Fe occupies an <a href="/facts/Octahedral_coordination_geometry/bNXLVvks">octahedral site</a> and the sulfide centers occupy <a href="/facts/Trigonal_prismatic_molecular_geometry/mw1kupQF">trigonal prismatic sites</a>.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> </p><p>Materials with the NiAs structure often are <a href="/facts/Non-stoichiometric/DAssoN0e">non-stoichiometric</a> because they lack up to 1/8th fraction of the metal ions, creating <a href="/facts/Vacancy_defect/kDeBLJIT">vacancies</a>. One of such structures is pyrrhotite-4C (Fe7S8). Here "4" indicates that iron vacancies define a <a href="/facts/Superlattice/nguy8U7X">superlattice</a> that is 4 times larger than the unit cell in the "C" direction. The C direction is conventionally chosen parallel to the main symmetry axis of the crystal; this direction usually corresponds to the largest lattice spacing. Other polytypes include: pyrrhotite-5C (Fe9S10), 6C (Fe11S12), 7C (Fe9S10) and 11C (Fe10S11). Every polytype can have monoclinic (M) or hexagonal (H) symmetry, and therefore some sources label them, for example, not as 6C, but 6H or 6M depending on the symmetry.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a><a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> The monoclinic forms are stable at temperatures below 254 °C, whereas the hexagonal forms are stable above that temperature. The exception is for those with high iron content, close to the troilite composition (47 to 50% atomic percent iron) which exhibit hexagonal symmetry.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> </p> <h2 id="magnetic-properties">Magnetic properties</h2> <p>The ideal FeS lattice, such as that of troilite, is non-magnetic. Magnetic properties vary with Fe content. More Fe-rich, hexagonal pyrrhotites are <a href="/facts/Antiferromagnetism/aQ124Kh7">antiferromagnetic</a>. However, the Fe-deficient, monoclinic Fe7S8 is <a href="/facts/Ferrimagnetism/sMcg7RYt">ferrimagnetic</a>.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> The <a href="/facts/Ferromagnetism/fH3HFnSl">ferromagnetism</a> which is widely observed in pyrrhotite is therefore attributed to the presence of relatively large concentrations of iron vacancies (up to 20%) in the crystal structure. Vacancies lower the crystal symmetry. Therefore, monoclinic forms of pyrrhotite are in general more defect-rich than the more symmetrical hexagonal forms, and thus are more magnetic.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a> Monoclinic pyrrhotite undergoes a magnetic transition known as the Besnus transition at 30 K that leads to a loss of magnetic remanence.<a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a> The <a href="/facts/Saturation_magnetization/QvhGEldn">saturation magnetization</a> of pyrrhotite is 0.12 <a href="/facts/Tesla_(unit)/K6I5Stn9">tesla</a>.<a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> </p> <h2 id="identification">Identification</h2> <h3>Physical properties</h3> <p>Pyrrhotite is brassy, bronze, or dark brown in color with a metallic <a href="/facts/Lustre_(mineralogy)/TCobwMGC">luster</a> and uneven or subconchoidal fracture.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a> Pyrrhotite may be confused with other brassy sulfide minerals like <a href="/facts/Pyrite/41CYREyr">pyrite</a>, <a href="/facts/Chalcopyrite/MXBDffGw">chalcopyrite</a>, or <a href="/facts/Pentlandite/kAmPYFqG">pentlandite</a>. Certain diagnostic characteristics can be used for identification in hand samples. Unlike other common brassy-colored <a href="/facts/Sulfide_mineral/f8rxJpCW">sulfide minerals</a>, pyrrhotite is typically magnetic (varies inversely with iron content).<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> On the <a href="/facts/Mohs_scale/wXBMcVIm">Mohs hardness scale</a>, pyrrhotite ranges from 3.5 to 4,<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> compared to 6 to 6.5 for pyrite.<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> <a href="/facts/Streak_(mineralogy)/BoMb1r1r">Streak</a> can be used when properties between pyrrhotite and other sulfide minerals are similar. Pyrrhotite displays a dark grey to black streak.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> Pyrite will display a greenish black to brownish black streak,<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> chalcopyrite will display a greenish black streak,<a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> and pentlandite leaves a pale bronze-brown streak.<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a> Pyrrhotite generally displays massive to granular <a href="/facts/Crystal_habit/x2S1HVVY">crystal habit</a>, and may show tabular/prismatic or hexagonal crystals which are sometimes <a href="/facts/Iridescence/ykc1opK8">iridescent</a>.<a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a> </p><p>Diagnostic characteristics in hand sample include: brassy/bronze color with a grey/black streak, tabular or hexagonal crystals which show iridescence, <a href="/facts/Fracture_(mineralogy)/Xzc4yDjy">subconchoidal fracture</a>, metallic luster, and magnetic. </p> <h3>Optical properties</h3> <p>Pyrrhotite is an opaque mineral and will therefore not transmit light. As a result, pyrrhotite will display <a href="/facts/Extinction_(optical_mineralogy)/EFSQDmAd">extinction</a> when viewed under plane polarized light and cross polarized light, making identification with <a href="/facts/Petrographic_microscope/A0LTduGv">petrographic polarizing light microscopes</a> difficult. Pyrrhotite, and other opaque minerals can be identified optically using a reflected light ore microscope.<a class="footnote-ref" id="fnref:20" href="#fn:20"><sup>20</sup></a> The following optical properties<a class="footnote-ref" id="fnref:21" href="#fn:21"><sup>21</sup></a> are representative of polished/puck sections using ore microscopy: </p> <p>Pyrrhotite typically appears as anhedral, granular aggregates and is cream-pink to brownish in color.<a class="footnote-ref" id="fnref:22" href="#fn:22"><sup>22</sup></a> Weak to strong reflection <a href="/facts/Pleochroism/EJJclyzk">pleochroism</a> which may be seen along grain boundaries.<a class="footnote-ref" id="fnref:23" href="#fn:23"><sup>23</sup></a> Pyrrhotite has similar polishing hardness to pentlandite (medium), is softer than pyrite, and harder than chalcopyrite.<a class="footnote-ref" id="fnref:24" href="#fn:24"><sup>24</sup></a> Pyrrhotite will not display <a href="/facts/Crystal_twinning/7xU6CKfR">twinning</a> or internal reflections, and its strong <a href="/facts/Anisotropy/YMqTQWVB">anisotropy</a> from yellow to greenish-gray or grayish-blue is characteristic.<a class="footnote-ref" id="fnref:25" href="#fn:25"><sup>25</sup></a> </p><p>Diagnostic characteristics in polished section include: anhedral aggregates, cream-pink to brown in color and strong anisotropy. </p> <h2 id="occurrence">Occurrence</h2> <p>Pyrrhotite is a rather common trace constituent of <a href="/facts/Mafic/mVL7Ahuw">mafic</a> <a href="/facts/Igneous_rocks/xeMJhUah">igneous rocks</a> especially <a href="/facts/Norite/uDGB2fLy">norites</a>. It occurs as segregation deposits in <a href="/facts/Layered_intrusion/LVIhCsfC">layered intrusions</a> associated with pentlandite, chalcopyrite and other sulfides. It is an important constituent of the <a href="/facts/Sudbury_Basin/poJSD267">Sudbury intrusion</a> (1.85 Ga old <a href="/facts/Impact_event/fbWu9Q4p">meteorite impact crater</a> in <a href="/facts/Ontario/HUkxk5Rf">Ontario</a>, Canada) where it occurs in masses associated with copper and nickel mineralisation.<a class="footnote-ref" id="fnref:26" href="#fn:26"><sup>26</sup></a> It also occurs in <a href="/facts/Pegmatite/qW5BUXPg">pegmatites</a> and in contact <a href="/facts/Metamorphic_rock/JRp6dsCm">metamorphic</a> zones. Pyrrhotite is often accompanied by pyrite, <a href="/facts/Marcasite/vP4CW3QC">marcasite</a> and magnetite. </p> <h2 id="formation">Formation</h2> <p>Pyrrhotite requires both iron and sulfur to form.<a class="footnote-ref" id="fnref:27" href="#fn:27"><sup>27</sup></a> Iron is the fourth most <a href="/facts/Abundance_of_elements_in_Earth%2527s_crust/UDSVHH56">abundant element</a> in the Earth's <a href="/facts/Continental_crust/cGnK3oEr">continental crust</a> (average abundance of 5.63 % or 56,300 mg/kg in the crust),<a class="footnote-ref" id="fnref:28" href="#fn:28"><sup>28</sup></a> and so the majority of rocks have sufficient iron abundance to form pyrrhotite.<a class="footnote-ref" id="fnref:29" href="#fn:29"><sup>29</sup></a> However, because sulfur is less abundant (average abundance of 0.035 % or 350 mg/kg in the crust),<a class="footnote-ref" id="fnref:30" href="#fn:30"><sup>30</sup></a> the formation of pyrrhotite is generally controlled by sulfur abundance.<a class="footnote-ref" id="fnref:31" href="#fn:31"><sup>31</sup></a> Also, the mineral <a href="/facts/Pyrite/41CYREyr">pyrite</a> is both the most common and most abundant sulfide mineral in the Earth's crust.<a class="footnote-ref" id="fnref:32" href="#fn:32"><sup>32</sup></a> If rocks containing pyrite undergo <a href="/facts/Metamorphism/8eWHgy6K">metamorphism</a>, there is a gradual release of <a href="/facts/Volatile_(astrogeology)/yYCe49qX">volatile</a> components like water and sulfur from pyrite.<a class="footnote-ref" id="fnref:33" href="#fn:33"><sup>33</sup></a> The loss of sulfur causes pyrite to <a href="/facts/Recrystallization_(geology)/vRoUTC3J">recrystallize</a> into pyrrhotite.<a class="footnote-ref" id="fnref:34" href="#fn:34"><sup>34</sup></a> </p><p>Pyrite also decomposes into pyrrhotite in hot reductive technogenic environments, such as <a href="/facts/Blast_furnace/DJzUB2EG">blast furnaces</a><a class="footnote-ref" id="fnref:35" href="#fn:35"><sup>35</sup></a> and <a href="/facts/Bergius_process/yEF6kS6M">direct coal liquefaction</a> (in which it is an important catalyst).<a class="footnote-ref" id="fnref:36" href="#fn:36"><sup>36</sup></a> </p><p>Pyrrhotite can also form near <a href="/facts/Hydrothermal_vent/0xPqNUkY">black smoker hydrothermal vents</a>.<a class="footnote-ref" id="fnref:37" href="#fn:37"><sup>37</sup></a> Black smokers release high sulfur concentrations onto the sea floor, and when the surrounding rocks are metamorphosed, pyrrhotite can crystallize.<a class="footnote-ref" id="fnref:38" href="#fn:38"><sup>38</sup></a> Later <a href="/facts/Ophiolite/vX9Kg940">tectonic processes</a> <a href="/facts/Obduction/5qSAGQhr">uplift</a> the metamorphic rocks and expose pyrrhotite to the Earth's surface.<a class="footnote-ref" id="fnref:39" href="#fn:39"><sup>39</sup></a> </p> <h2 id="distribution">Distribution</h2> <h3>United States</h3> <p>Pyrrhotite occurs in a variety of locations in the <a href="/facts/United_States/P0sCdLe5">United States</a>.<a class="footnote-ref" id="fnref:40" href="#fn:40"><sup>40</sup></a><a class="footnote-ref" id="fnref:41" href="#fn:41"><sup>41</sup></a><a class="footnote-ref" id="fnref:42" href="#fn:42"><sup>42</sup></a><a class="footnote-ref" id="fnref:43" href="#fn:43"><sup>43</sup></a> In the <a href="/facts/Eastern_United_States/VnPT6jFW">eastern United States</a>, pyrrhotite occurs in highly <a href="/facts/Metamorphic_rock/JRp6dsCm">metamorphosed</a> rock that forms a belt along the <a href="/facts/Appalachian_Mountains/f7X1GBDE">Appalachian Mountains</a>.<a class="footnote-ref" id="fnref:44" href="#fn:44"><sup>44</sup></a> Pyrrhotite-bearing rocks are generally unseen in the <a href="/facts/Central_United_States/kHodBbwQ">central United States</a> as the area is unmetamorphosed and underlain by <a href="/facts/Sedimentary_rock/HQDCjrco">sedimentary rocks</a> which do not contain pyrrhotite.<a class="footnote-ref" id="fnref:45" href="#fn:45"><sup>45</sup></a> Discontinuous <a href="/facts/Orogenic_belt/wuItj62U">belts</a> that contain pyrrhotite are present in the <a href="/facts/Western_United_States/uY9UGAus">western United States</a> along the <a href="/facts/Sierra_Nevada/tKcI8PeH">Sierra Nevada mountain range</a> and <a href="/facts/Cascade_Range/v7n1chTV">Cascade Range</a> extending into the <a href="/facts/Northwestern_United_States/wymn1rdL">northwestern United States</a>.<a class="footnote-ref" id="fnref:46" href="#fn:46"><sup>46</sup></a> Pyrrhotite may also be found west and south of <a href="/facts/Lake_Superior/o6hh85hD">Lake Superior</a>.<a class="footnote-ref" id="fnref:47" href="#fn:47"><sup>47</sup></a> </p> <h2 id="mining-locations-worldwide">Mining locations worldwide</h2> <p>The following are some of the locations worldwide where pyrrhotite has been reported during <a href="/facts/Mining/g6uDIFab">mining</a>:<a class="footnote-ref" id="fnref:48" href="#fn:48"><sup>48</sup></a> </p> <h3>Canada</h3> <table><tbody><tr><th>Location</th><th>Mine</th><th>Main Target Commodities</th></tr><tr><td><a href="/facts/British_Columbia/Ty3e3g1Q">British Columbia</a>, <a href="/facts/Riondel%2c_British_Columbia/rV2z3By1">Riondel</a></td><td>Bluebell Mine<a class="footnote-ref" id="fnref:49" href="#fn:49"><sup>49</sup></a></td><td><a href="/facts/Cadmium/wXkV2eIX">Cd</a>, <a href="/facts/Copper/I8PEE8oX">Cu</a>, <a href="/facts/Gold/1znknojp">Au</a>, <a href="/facts/Lead/EYljasJN">Pb</a>, <a href="/facts/Silver/xXe41BGg">Ag</a>, <a href="/facts/Zinc/80b1qgk3">Zn</a></td></tr><tr><td><a href="/facts/Quebec/4hhNvb4t">Québec</a></td><td>Henderson No. 2 mine (Copper Rand mine)<a class="footnote-ref" id="fnref:50" href="#fn:50"><sup>50</sup></a></td><td><a href="/facts/Copper/I8PEE8oX">Cu</a>, <a href="/facts/Gold/1znknojp">Au</a></td></tr><tr><td><a href="/facts/Quebec/4hhNvb4t">Québec</a></td><td>B&B Quarry, Sharwinigan</td><td>Crushed rock (Gabbro) for construction</td></tr><tr><td><a href="/facts/Quebec/4hhNvb4t">Québec</a></td><td>Maskimo Quarry, Sharwinigan</td><td>Crushed rock (Gabbro) for construction</td></tr></tbody></table> <h3>US</h3> <table><tbody><tr><th>Location</th><th>Mine</th><th>Main Target Commodities</th></tr><tr><td><a href="/facts/Connecticut/LeDhYdJG">Connecticut</a></td><td>Becker Quarry (Becker's Quarry)<a class="footnote-ref" id="fnref:51" href="#fn:51"><sup>51</sup></a></td><td>Not given, but abundant <a href="/facts/Quartz/4n86tE2G">quartz</a>, <a href="/facts/Kyanite/hYsGBwc3">kyanite</a>, and <a href="/facts/Garnet/kqh2lWQI">garnet</a> are worthy of mentioning.<p>Note: This was a quarry producing crushed rock aggregate for use in construction</p></td></tr></tbody></table> <h3>Australia</h3> <table><tbody><tr><th>Location</th><th>Mine</th><th>Main Target Commodities</th></tr><tr><td><a href="/facts/Tasmania/q3dubPTt">Tasmania</a></td><td><a href="/facts/Renison_Bell/mxteluIJ">Renison Bell Mine</a> (Renison Mine)<a class="footnote-ref" id="fnref:52" href="#fn:52"><sup>52</sup></a></td><td><a href="/facts/Tin/obW9mqc3">Sn</a></td></tr></tbody></table> <h3>Brazil</h3> <table><tbody><tr><th>Location</th><th>Mine</th><th>Main Target Commodities</th></tr><tr><td><a href="/facts/Minas_Gerais/73LdwKnD">Minas Gerais</a></td><td><a href="/facts/Morro_Velho/17atWAQI">Morro Velho mine</a><a class="footnote-ref" id="fnref:53" href="#fn:53"><sup>53</sup></a><a class="footnote-ref" id="fnref:54" href="#fn:54"><sup>54</sup></a></td><td><a href="/facts/Gold/1znknojp">Au</a>, <a href="/facts/Iron_ore/rQMEvgMh">iron-ore</a><a class="footnote-ref" id="fnref:55" href="#fn:55"><sup>55</sup></a></td></tr></tbody></table> <h3>Italy</h3> <table><tbody><tr><th>Location</th><th>Mine</th><th>Main Target Commodities</th></tr><tr><td><a href="/facts/Tuscany/Ivw1ogrE">Tuscany</a></td><td>Bottino Mine<a class="footnote-ref" id="fnref:56" href="#fn:56"><sup>56</sup></a></td><td><a href="/facts/Silver/xXe41BGg">Ag</a>, <a href="/facts/Sulfide/d8YMjLeu">sulfides</a><a class="footnote-ref" id="fnref:57" href="#fn:57"><sup>57</sup></a></td></tr></tbody></table> <h3>Kosovo</h3> <table><tbody><tr><th>Location</th><th>Mine</th><th>Main Target Commodities</th></tr><tr><td><a href="/facts/District_of_Mitrovica/sc3b21IS">Mitrovica District</a></td><td>Trepça Mine<a class="footnote-ref" id="fnref:58" href="#fn:58"><sup>58</sup></a></td><td><a href="/facts/Lead/EYljasJN">Pb</a>, <a href="/facts/Silver/xXe41BGg">Ag</a>, <a href="/facts/Silver/xXe41BGg">Zn</a></td></tr></tbody></table> <h2 id="etymology-and-history">Etymology and history</h2> <p>Named in 1847 by <a href="/facts/Ours-Pierre-Armand_Petit-Dufr%25C3%25A9noy/DoSqsd0u">Ours-Pierre-Armand Petit-Dufrénoy</a>.<a class="footnote-ref" id="fnref:59" href="#fn:59"><sup>59</sup></a> "Pyrrhotite" is derived from the <a href="/facts/Greek_language/pzDd6eIz">Greek</a> word πυρρός, "<i><a href="/facts/Pyrrhus_of_Epirus/9lG2ucMh">pyrrhos"</a></i>, meaning flame-colored.<a class="footnote-ref" id="fnref:60" href="#fn:60"><sup>60</sup></a> </p> <h2 id="issues">Issues</h2> <p>If pyrrhotite-containing rocks are crushed and used as aggregate within concrete, then the pyrrhotite creates a problem in the production of <a href="/facts/Concrete/K6whGVNx">concrete</a>.<a class="footnote-ref" id="fnref:61" href="#fn:61"><sup>61</sup></a> Pyrrhotite has been linked to <a href="/facts/Concrete_degradation/vrN0hImA">crumbling concrete basements</a> in <a href="/facts/Quebec/4hhNvb4t">Quebec</a>, <a href="/facts/Massachusetts/9uumCbFI">Massachusetts</a> and <a href="/facts/Connecticut/LeDhYdJG">Connecticut</a> when local <a href="/facts/Quarry/s6fhrNhe">quarries</a> included it in their concrete mixtures.<a class="footnote-ref" id="fnref:62" href="#fn:62"><sup>62</sup></a><a class="footnote-ref" id="fnref:63" href="#fn:63"><sup>63</sup></a><a class="footnote-ref" id="fnref:64" href="#fn:64"><sup>64</sup></a> Many houses in Ireland, particularly in County Donegal, have also been affected by inclusion of rocks containing pyrrhotite in concrete blocks.<a class="footnote-ref" id="fnref:65" href="#fn:65"><sup>65</sup></a><a class="footnote-ref" id="fnref:66" href="#fn:66"><sup>66</sup></a> The <a href="/facts/Iron_sulfide/EJQPNLFT">iron sulfide</a> it contains can naturally react with <a href="/facts/Oxygen/acyn6o8r">oxygen</a> and water, and over time pyrrhotite breaks down into <a href="/facts/Sulfuric_acid/Wom6fymJ">sulfuric acid</a> and <a href="/facts/Secondary_mineral/vLoLTKUF">secondary minerals</a> like <a href="/facts/Ettringite/yN9up1Ur">ettringite</a>, <a href="/facts/Thaumasite/T5lGfGvM">thaumasite</a> and <a href="/facts/Gypsum/MItYU70n">gypsum</a>.<a class="footnote-ref" id="fnref:67" href="#fn:67"><sup>67</sup></a><a class="footnote-ref" id="fnref:68" href="#fn:68"><sup>68</sup></a> These secondary products occupy a larger volume than pyrrhotite, which expands and cracks the concrete leading to home foundation or block failure.<a class="footnote-ref" id="fnref:69" href="#fn:69"><sup>69</sup></a><a class="footnote-ref" id="fnref:70" href="#fn:70"><sup>70</sup></a><a class="footnote-ref" id="fnref:71" href="#fn:71"><sup>71</sup></a><a class="footnote-ref" id="fnref:72" href="#fn:72"><sup>72</sup></a><a class="footnote-ref" id="fnref:73" href="#fn:73"><sup>73</sup></a> </p> <h2 id="uses">Uses</h2> <p>Other than a source of <a href="/facts/Sulfur/IK0amTfM">sulfur</a>, pyrrhotite does not have specific applications.<a class="footnote-ref" id="fnref:74" href="#fn:74"><sup>74</sup></a> It is generally not a valuable mineral unless significant <a href="/facts/Nickel/KwMCHYRP">nickel</a>, <a href="/facts/Copper/I8PEE8oX">copper</a>, or other metals are present.<a class="footnote-ref" id="fnref:75" href="#fn:75"><sup>75</sup></a><a class="footnote-ref" id="fnref:76" href="#fn:76"><sup>76</sup></a> <a href="/facts/Iron/QK1JYy8E">Iron</a> is seldom extracted from pyrrhotite due to a complicated <a href="/facts/Metallurgy/1SANyxX4">metallurgical process</a><a class="footnote-ref" id="fnref:77" href="#fn:77"><sup>77</sup></a> It is mined primarily because it is associated with <a href="/facts/Pentlandite/kAmPYFqG">pentlandite</a>, a sulfide mineral that can contain significant amounts of nickel and <a href="/facts/Cobalt/gqhScEw4">cobalt</a>.<a class="footnote-ref" id="fnref:78" href="#fn:78"><sup>78</sup></a> When found in <a href="/facts/Mafic/mVL7Ahuw">mafic</a> and <a href="/facts/Ultramafic_rock/7qAapP1d">ultramafic</a> rocks, pyrrhotite can be a good indicator of economic <a href="/facts/Nickel/KwMCHYRP">nickel deposits</a>.<a class="footnote-ref" id="fnref:79" href="#fn:79"><sup>79</sup></a> </p> <h2 id="mineral-abbreviations">Mineral abbreviations</h2> Table of pyrrhotite mineral abbreviations. <i>Note:</i> only use official IMA-CNMNC symbol listed in bold text.<table><tbody><tr><th>Abbreviation</th><th>Source</th></tr><tr><td>Pyh</td><td>IMA-CNMNC<a class="footnote-ref" id="fnref:80" href="#fn:80"><sup>80</sup></a></td></tr><tr><td>Po</td><td>Whitney and Evans, 2010;<a class="footnote-ref" id="fnref:81" href="#fn:81"><sup>81</sup></a> The Canadian Mineralogist, 2019.<a class="footnote-ref" id="fnref:82" href="#fn:82"><sup>82</sup></a></td></tr></tbody></table> <h2 id="synonyms">Synonyms</h2> Synonyms of the mineral pyrrhotite.<a class="footnote-ref" id="fnref:83" href="#fn:83"><sup>83</sup></a><table><tbody><tr><td>Magnetic pyrite</td><td>Magnetopyrite</td><td>Magnetic pyrites</td></tr><tr><td>Pyrrhotine</td><td>Pyrrohotite</td><td>Magnetic iron pyrites</td></tr><tr><td>Dipyrite</td><td>Kroeberite</td><td>Vattenkies</td></tr></tbody></table> <h2 id="external-links">External links</h2> <ul><li><a href="/facts/Leonard_James_Spencer/yuVCYogn">Spencer, Leonard James</a> (1911). <a href="https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica/Pyrrhotite">"Pyrrhotite" </a>. <i><a 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