Iron pyrite

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Frequency	{{{3}}}}}}}{{#if:6-6.5|
Hardness	{{{3}}}}}}}{{#if:5|
Density	{{{3}}}}}}}
Chemical Formula	{{#Chem:FeS2}}|unspecified}}{{ if:Fe|
Core Elements	, {{{m2}}}}}{{ if:|, {{{m3}}}}}{{ if:|
{{ if:Fe2O3|
Thermal Decomposition	{{{env}}}, }}540-850°C{{#if:|, {{{energy}}}}} {{#Chem:Fe2O3}}

pyrite, along with Hematite and Magnetite is a primary ore of iron.

Weathering

In contact with a wet natural environment (water, air, perhaps sunlight), pyrite weathers producing ferrous (and perhaps ferric) sulfates:

{{#Chem: 4FeS2(s) + 14O2(g) + 4H2O(l)  =  4FeII + 8SO42- + 8H+}}
{{#Chem: 4FeII + O2 + 4H+  =   4FeIII + 2H2O}}
{{#Chem: 4FeIII + 12 H2O  =    4Fe(OH)3 + 12H+}}