The largest producer of single crystals is nature. Large (centimeter-range) single crystals of many naturally occurring compounds, usually called minerals, have long been valued for their beauty and have raised many questions that led to understanding the structure of matter. Their characteristic habits, with well-developed natural faces, occur when their growth process involves isotropic enough an environment as well as enough space. The typical process, hydrothermal growth, is based on the slow deposition of a solute as the temperature of the solution changes, and it is often associated with high pressures. Among the most popular examples of minerals are quartz SiO2 (rock crysta ,(calcite CaCO3 (Iceland spar), diamond C, pyrite FeS2 (fool’s gold). They may well, through their beauty, have kindled the reader’s interest for crystals and symmetry. Other materials crystallize very easily, at room pressure and room temperature, from solutions: this is the case for sodium chloride NaCl (rocksalt), or copper sulfate CuSO4. Crystallization is then a convenient way of purifying the material.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
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