Belite crystals have been observed that show only one set of striations.
whose behaviour in transmitted light between crossed polars shows them to
be twin lamellae. Such crystals are typically irregular in shape; they have
been called Type 11 belites, and are rare in modern clhkers. The striations
arise from the a', to !3 transformation. Such crystals can form either by crystallization from the liquid below the u to u',, transition tempcruture. or
by slow cooling of a-C,S under conditions such that one of the twin
components of the resulting a' modification has grown at the expense of the
others. These two modes of formation can be distinguished morphologically.
the second mode giving larger and less rounded grains (01). Belite forms in
clinkers by additional mechanisms, sometimes at lower tenipcrat~~rcths an
those discussed above, and may not then show any striations.