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Crystal growth from solution phases is most universal and important in natural crystallization. Its essential features are : 1) mass transfer and 2) interaction between solid and liquid phases, in addition to lower growth temperatures, and, in general, smoother solid-liquid interfaces, as compared to melt growth. The morphology of crystals changes depending on the degree of supersaturation σ in solution growth, and there are two transitional supersaturations σ* and σ**, where transitions from bulky to hopper, and from hopper to dendritic morphologies occur, respectively. Changes of morphology during crystal growth (internal morphology) may be analysed on this basis. The σ* and σ** vary depending on materials and environmental conditions. Surface microtopographies of crystal faces of natural crystals are analysed using α-factors and γ, Δμ/kT, and compared with laboratorically synthesized crystals, and characteristics of natural crystallization are discussed. Growth under metamorphic and metasomatic conditions are also analysed based on the surface microtopographic observations.

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