Crystallized Carbonate of Lime
This crystal is from the same county as tab. 436, and is terminated by one of the dodecaëdral modifications of Count de Bournon. It is remarkable for being nearly halved by two adjoining faces of the metastatic modification being very deeply cut. Thus we find that the crystals of Carbonate of Lime not only have many modifications, but they are so placed, and more or less enlarged, as to be much disguised, and even exhibit mere halves of a modification, the four faces of the pyramid being two of them perfect, and the other two only equal to a third, form a quarter of a dodecaëdron or half the six-sided pyramid.