593. There does not exist in nature an order of silex, clay, or talc, so soon as we take up these earths in a simply chemical manner. Nature instead of silex produces quartz, instead of clay feldspar, instead of talc mica; and these must be the earths, that determine this part of the mineral system; they are the characters of orders; there is thus properly no order of silex but of quartz, none of clay but of feldspar, none of talc but of mica, at least according to their signification.
594. The points of origin for this division of the mineral system or that formed by the fundamental earths are the three fundamental crystallizations, and upon these _everything_ that does not belong to the calcareous earth must and does naturally arrange itself. The mineral system is only the developed and separated granite. The fact cannot rest unobserved, that mica has only one laminar cleavage, feldspar two, quartz three, this being for the first time a perfect crystal, a double tetrahedron with one column.
595. With granite and with it alone the solidity, the body and form of the earth has been given; it is the homogeneous fundamental mass of the planet, and is therefore crystallized throughout to the finest degree in its three constituent forms.
596. If, in addition to granite, several formations are displayed which bear traces of the same mode of origin, of the same component parts and the same aggregation, it may be inferred that they are only metamorphoses of the same precipitate. Granite is the basis of geogeny.
597. Granite is a totality for the earth, it is a representation of the three terrestrial elements under the form of identical earth; it is the earth represented in silex, water in clay, and air in talc; it is an universe represented individually in the earth-elements.
598. The granite can undergo metamorphosis in only three ways; for its essence is indeed only trinity. Nothing can individualize itself from granite but quartz, feldspar, and mica. All the formations of this period are thus _quartz_, _feldspar_, or _mica formations_. The granite appears under a threefold form as quartz, feldspar, and mica-granite.
599. The first quartz formation is properly the granite itself, and its character will be also the determinant for all the metamorphoses of quartz--quartz-granite.