. Author manuscript; available in PMC: 2019 Apr 24.

Published in final edited form as: Meteorit Planet Sci. 2015 Apr 24;50(5):976–1004. doi: 10.1111/maps.12445

Table 2.

Iris chromite compositions from TEM and SEM EDS.

	Normalized Oxide Weight %
Spectrum	SiO₂	TiO₂	Al₂O₃	V₂O₃	Cr₂O₃	Fe₂O₃	MgO	MnO	FeO	t (nm)
TEM 24	0.00^a	1.80	17.90		43.99	2.85	5.69		27.78	100^b
TEM 25	0.00^a	1.19	19.03	0.48	45.04	2.18	6.15	0.81	25.13	260
TEM 26	1.48	2.48	14.94		47.10	0	5.90		28.10	150
SEM 10	0.73	1.91	14.12	0.57	45.80	3.93	5.75	0.76	26.43	n/a.^c
	Cations per 4 oxygens
Spectrum	Si	Ti	Al	V	Cr	Fe³⁺	Mg	Mn	Fe²⁺	Fe³⁺/ΣFe

TEM 24	0.000	0.045	0.695		1.146	0.071	0.279		0.765	0.08
TEM 25	0.000	0.029	0.734	0.006	1.166	0.054	0.300	0.022	0.688	0.07
TEM 26	0.066	0.083	0.789		1.668	0.000	0.394		1.053	0.00
SEM 10	0.024	0.048	0.558	0.008	1.213	0.099	0.287	0.022	0.741	0.12

SiO₂ contribution removed. If some glass was present in the spectrum, this could influence other elements.

We used a thin film correction based on STXM thickness (t) measurements. Where no STXM measurement was available, we assumed a nominal 100 nm correction.

We used the XPP matrix correction on SEM measurements.