Crystal habits

Keywords Zeolite L, Crystal Habit, Crystal Growth, AFM... 

Habit, Crystals usually broad tabular 0001) often subparallel aggregates of plates a manganoan Texas, Pa. variety is sometimes acicular [0001]. 

Crystals are ordered atoms (or molecules) in a crystal lattice. This internal structure is accessible by x-ray diffraction and is available for most cortunon solids. Unless a crystal displays polymorphism, the crystals internal structure will not vary with the conditions of its growth. This, however, is not the case for the external crystal habit. Crystal habit can vary with the conditions of growth, solvent used and the presence of impurities. 

Fig. 2.13 Demonstration of the difference between crystal habit and polymorphic form for the three polymorphs of naphthazarin. Upper left, polymorph A upper right, polymorph B lower, polymorph C in two different habits. (Crystals prepared and photos taken by Kress and Etter 1989.)...

One of the many unique features of crystals is crystal habits. Crystals can have different shapes and faces that make them unique and distinct from hquid or gaseous materials. In view of the focus of this book, crystal morphology means the approximate shape of crystals. Our purpose is to describe quahtatively the aspect ratios of crystals in three-dimensional space with relevance to the crystallization process. Therefore, we refer the reader to (Mullin 2001, Chapter 1) for a more thorough and comprehensive classifications of crystal morphology. 

In our discussions of crystals to this point, we have been discussing the internal structure of the crystals, that is, how the atoms and molecules are arranged into their periodic lattice structure. The external appearance of the crystals is also of great importance and is referred to as the crystals habit, crystal shape, or crystal morphology. These terms are often used interchangeably, however, crystal habit is used most often. 

Alite—crystal size, optics, zoning, fringing, habit, crystal form ... 

Crystal system Crystal habit Crystal oii tation Crystal habit Cr itd orientation Cr tal habit Crystal orientation... 

Empirical Formula Formula Weight Crystal Color, Habit Crystal Dimensions, mm Crystal System No. Reflections Used for Unit Cell Determination, (26 range, deg) Space Group... 

Cordierite insulator has the formula 2Mg0-2Al203-5Si02. A variety of fluxes are used in its manufacture. The cordierite phase develops as prismatic habit crystals. These are again bonded with a glassy phase. In addition, some mullite, corundum, spinel, forsterite, or enstatite (Mg0-Si02) phases may also be seen. 

Crystals of Kq 30M0O3 are shiny metallic blue and grow with a elongated tabular habit. Crystals are monoclinic, space group C2/M, with lattice constants, a = 18.249(10) A, h = 7.560(5) A, c = 9.855(6) A, and... 

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