The first parameter is the literal or column value on which you want the SUBSTR function to operate. The second parameter is the position of the starting character for the substring, and the optional third parameter is the number of characters to be included in the substring.If the third parameter is not specified, the SUBSTR function will return the remainder of the string.he second parameter is the position of the starting character for the substring, and the optional third parameter is the number of characters to be included in the substring. If the third parameter is not specified, the SUBSTR function will return the remainder of the string.
There are two basic types of metamorphic rocks. Foliated metamorphic rocks such as gneiss, phyllite, schist, and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure. Non-foliated metamorphic rocks such as hornfels, marble, quartzite, and novaculite do not have a layered or banded appearance.
Kinds of Metamorphic Rocks â¢Gneiss-a coarse grained granular rock in which foliation results from alternating layers of light and dark minerals. Compositionally similar to granite with quartz, feldspar, biotite, and amphibole. Forms during regional high grade metamorphism.inds of Metamorphic Rocks â¢ Slate-low grade metamorphosed shale; very fine grained; slaty cleavage should not be confused with bedding planes.â¢ Phyllite-next step up from slate, larger mica grains give the rock a luster.â¢Schist-a strongly foliated rock with large grains of platy minerals.