Abstract
Crystal growth accompanied with the liquid-solid transformations in several materials are observed under high pressure up to 25 kbar at room temperature. Diamond-anvil type high pressure apparatus and optical microscope were used for these observations. Materials studied are: liquid-ice VI-ice VII transformation in H_2O, liquid-solid transformations in carbon tetrachloride (CCI_4), ethyl alcohol (C_2H_5OH), and benzene (C_6H_6). Dissolution of calcite (CaCO_3) and a growth of ikaite (CaCO_3・6H_2O) under high water pressure were also observed. These observations provide us many informations for the structure and the growth mechanism of these crystals.
