Calcite bladed

Figure 11.7 Scanning electron microscopy images of marine beachrock and meteoric cayrock cements. (A) Blades of high-magnesium calcite on constituent particles in beachrock. Northeast Sapodilla Cay, southern Belize Barrier Reef. (B) Dissolution cavity is lined with blockyand bladed low-magnesium calcite in cayrock. Cay Bokel, Turneffe Islands, Belize. (C) Low-magnesium calcite needle fibre (whisker) cement in cayrock. Harry Jones Point, Turneffe Islands, Belize.

Calcite cements associated with these concretions are dominantly micritic and exhibit circumgranular cracking, alveolar, micrite-spar and meniscus microtextures. Radial spar microtexture is present locally, characterized by bladed radial spar formed around a micritic nucleus (Fig. 1OD). 

Ashton and Valentin compared the performance of an Airmix, Nautamix, Oblicone and Z-biade mixer using equi-sized particles of sand and calcite. The mixture quality achieved approached that of the random mixture quality in all four mixers but this condition was achieved most rapidly in the Airmix followed by the Oblicone, Nauta and Z-blade mixers. When testing the effect of mixer variables on the quality of mixing achieved it was found that the tumbler mixer permance was very dependent on rotational speed. 

Wollastonite is a naturally occurring, nondurable calcium silicate derived from metamorphosed impure limestone. It rarely occurs in pure form and is most commonly associated with calcite, quartz, garnet, and diopside. Morphologically, wollastonite can be found as a coarse-bladed, acicular or fibrous structure. Wollastonite was first mined for the production of mineral wool. Current uses of... 

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