Photomicrographs Illustrating Onos Method

Photograph 6-1 One s method for apparent birefringence of alite in powder mount. Crystal length-to-width ratio = approximately 2 1. Ono measures particle width. Other observers, the present writer included, measure crystal width. (S A6616) 

Transmitted, plane-polarized light Field dimensions = 0.21x0.21 mm 

Photograph 6-2 Same as Photograph 6-1 but in cross polars and 45° from the extinction position. (S A6617) 

Photograph 6-4 Clear to faint yellow, round belite crystals in powder mount (44- to 75-pm fraction). Fast to moderately fast cooling. Coal- and coke-fired, dry-process kiln, 45 MPa. (S A6619) 

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