Granite is an igneous rock with a coarse texture and grain size > 3 mm (plutonic). Gabbros are basic rocks, with a total silica content of 45-55%.Predominent minerals in this generally dark colored rock are the ferromagnesium minerals (hornblende, olivine, pyroxene) and plagioclase feldspar. Property values are typical of Gabbro used in construction. Actual property values will vary from sample to sample. |