Table 2. Grain size distribution (% mass) of loading agents used in Phase 2.

Loading Agent†	Source and Note	Coarse Sand (0.5–1.0 mm)	Medium Sand (0.25–0.5 mm)	Fine Sand (125–250 µm)	Very Fine Sand (62.5–125 µm)	Silt + Clay (<62.5 µm)	Loading Agent Particle Size Rank
#1: Silt and Clay‡	Sigma-Aldrich reports ∼1% colloidal (<1 µm) particles.	0	0	0	0	99	1
#2: Medium Sand Mix	Hebei Yunsong Trade Co.	20.2	71.6	7.7	0.14	0.36	5
#3: Fine Sand Mix	Hebei Yunsong Trade Co.	0	0.26	80.79	18.71	0.24	3
#4: Silt and Clay Mix	Hebei Yunsong Trade Co.	0	0	0.2	2.05	97.75	2
#5: Medium Sand Only	Separated from #2.	0	100	0	0	0	6
#6: Fine Sand Only	Separated from #2.	0	0	100	0	0	4
#7: Coarse Sand Only	Separated from #2.	100	0	0	0	0	7

^†All materials were purchased from commercial suppliers and reported as 100% Silicon Dioxide by their manufacturer.

^‡#1 is the same loading agent as Silicon Dioxide #S5631 in Table 1.

Ranked in ascending order from finest to coarsest by percent of each particle size class represented in the loading agent.