Table 3.

Assignment of Complex Refractive Indexes to Particle Phases: Los Angeles Particles

				Complex Refractive Index
Particle	Material Phase		Percent Volume	Real Part	Imaginary Part	References
LA1	Single phases	BC	36.8	1.95	0.79	Bond and Bergstrom [2006]
		Graphite	36.8	2.65	1.39	Stagg and Charalampopoulos [1993]
		Montmorillonite	42.9	1.52	0.000035	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-19]
		Calcite	10.0	1.49	∼0	Anthony et al. [2016]
		(NH4)2SO4	5.30	1.53	∼0	Toon et al. [1976]
		Biotite	3.39	1.65	0.00034	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-22]
		Rutile	1.59	2.90	∼0	Anthony et al. [2016]
	Combined phasesa	BC + (NH4)2SO4 + Montmorillonite + Calcite + Biotite + Rutile	100	1.746	0.389	Bond and Bergstrom [2006], Toon et al. [1976], Anthony et al. [2016], and Egan and Hilgeman [1979, Tables V-19 and V-22]
		Graphite + (NH4)2SO4 + Montmorillonite + Calcite + Biotite + Rutile	100	2.071	0.725	Stagg and Charalampopoulos [1993], Toon et al. [1976], Anthony et al. [2016], and Egan and Hilgeman [1979, Tables V-19 and V-22]
LA2	Single phases	BC (soot)	72.5	1.95	0.79	Bond and Bergstrom [2006]
		Graphite	72.5	2.65	1.39	Stagg and Charalampopoulos [1993]
		(NH4)2SO4	10.7	1.53	∼0	Toon et al. [1976]
		Biotite	9.78	1.65	0.00034	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-22]
		Kaolinite	6.78	1.56	0.000038	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-15]
	Combined phasesa	BC + (NH4)2SO4 + Biotite + Kaolinite	99.8	1.807	0.479	Bond and Bergstrom [2006], Toon et al. [1976], Anthony et al. [2016], and Egan and Hilgeman [1979, Tables V-22 and V-15]
		Graphite + (NH4)2SO4 + Biotite + Kaolinite	99.8	2.215	0.874	Stagg and Charalampopoulos [1993], Toon et al. [1976], Anthony et al. [2016], and Egan and Hilgeman [1979, Tables V-22 and V-15]
LA3	Single phases	Hematite	76.9	2.91	0.1	Anthony et al. [2016] and Sokolik and Toon [1999]
		Limonite	76.7	2.46	0.0042	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-16]
		Goethite	76.7	2.46	0.08	Anthony et al. [2016] and Bedidi and Cervelle [1993]
		BaO	11.8b13.3c	1.99	0.0003	Anderson and Hensley [1975]
		(NH4)2SO4	8.44b7.11c	1.53	∼0	Toon et al. [1976]
		Al2O3	1.83	1.76	∼0	Anthony et al. [2016]
		BC	0.66	1.95	0.79	Bond and Bergstrom [2006]
	Combined phasesa	Hematite + BaO + (NH4)2SO4 + Al2O3	98.9	2.566	0.0721	Anthony et al. [2016], Sokolik and Toon [1999], Anderson and Hensley [1975], and Toon et al. [1976]
		Limonite + BaO + (NH4)2SO4 + Al2O3	98.9	2.293	0.00316	Anthony et al. [2016], Egan and Hilgeman [1979, Table V-16], Anderson and Hensley [1975], and Toon et al. [1976]
		Goethite + BaO + (NH4)2SO4 + Al2O3	98.9	2.293	0.0600	Anthony et al. [2016], Bedidi and Cervelle [1993], and Anderson and Hensley [1975]
LA4	Single phases	Albited	1.32 38.9	1.54	0.000035	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-10]
		Quartz	22.2	1.55	∼0	Anthony et al. [2016]
		Almandine	27.4	1.83	0.00034	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-22]
		Pyrope	10.1	1.71	0.00034	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-22]
		Illite	21.5e19.7f	1.41	0.00071	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-14]
		Kaolinite	8.04e7.36f	1.56	0.000038	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-15]
		Hematite	7.91	2.91	0.1	Anthony et al. [2016] and Sokolik and Toon [1999]
		Limonite	10.4	2.46	0.0042	Anthony et al. [2016] and Egan and Hilgeman [1979, Table V-16]
		Goethite	10.4	2.46	0.08	Anthony et al. [2016] and Bedidi and Cervelle [1993]
	Combined phasesa	Albite + Almandine + Pyrope + Quartz + Albite	99.9	1.637	0.000136	Anthony et al. [2016] and Egan and Hilgeman [1979, Tables V-10 and V-22]
		Albite + Illiite/Kaolinite/Hematite + Quartz + Albite	99.9	1.598	0.00433	Anthony et al. [2016], Egan and Hilgeman [1979, Tables V-10, V-14, and V-15], and Sokolik and Toon [1999]
		Albite + Illiite/Kaolinite/Limonite + Quartz + Albite	99.9	1.598	0.000471	Anthony et al. [2016] and Egan and Hilgeman [1979, Tables V-10, V-14, V-15, and V-16]
		Albite + Illiite/Kaolinite/Goethite + Quartz + Albite	99.9	1.598	0.00580	Anthony et al. [2016], Egan and Hilgeman [1979, Tables V-10, V-14, and V-15], and Bedidi and Cervelle [1993]

^aOptical properties for combined phases are calculated from Maxwell-Garnett dielectric function (see equations (1)–(3)). The real part of the Maxwell-Garnett function ε′ = n^b – k^b, where n and k are the real and imaginary parts of the refractive index. Likewise, the imaginary part of the Maxwell-Garnett function ε″ = 2nk.

^bVolume if phase is associated with hematite.

^cVolume if phase is associated with goethite.

^dParticle contains two albite phases.

^eVolume if phase is associated with hematite.

^fVolume if phase is associated with either goethite or limonite.