Table 1.

Assignment of Miller indices (hkl) to the peaks observed in Figure 1.

Peak Position (Å)	Assignment (hkl)a)
	Mackinawite	Greigite	Pyrite
1.63			(311)* b)
1.75		(440)*
1.84	(200)*
1.92		(511)	(220)
2.21			(211)
2.31	(111)
2.42		(400)	(210)
2.71			(200)*
2.98	(101)	(311)
3.13			(111)

a) JCPDS International Center for Diffraction Data, 2001: mackinawite 24-0073, greigite 16-0713, pyrite 42-1340.

b) marked peaks (*) were used to calculate the reaction progress variable α.