Figure 8.3.2. Clinker polished section with a nital etch at 400X, showing uniformly distributed silicates and a finely microcrys- talline matrix of aluminate (C3A) and ferrite, the latter dominant. AS = 54, AB = 0.0089, BS = 31, BC = pale yellow to yellow. Alite:Belite (25-32-micron KOH residue) = 90.1%:9.1% = 9.9. One belite nest fragment with tightly packed crystals in 409 grains of the 32- to 75- micron fraction of crushed clinker. ICMA Sample Exchange Program, Sample #67. FL = 140 microns.