Igneous rocks - Sandatlas
Illustrated overview and examples of igneous rocks: basalt, granite, obsidian, pumice, gabbro, porphyry...
Porphyry - Igneous Rocks - Sandatlas
Porphyry is an igneous rock characterized by porphyritic texture. Porphyritic texture is a very common texture in igneous rocks in which larger crystals (phenocrysts ...
rock , Definition, Characteristics, & Types , Britannica.com
General considerations Rock types. Igneous rocks are those that solidify from magma, a molten mixture of rock-forming minerals and usually volatiles such as gases and ...
The Quartz Page: Quartz as a Rock-Forming Mineral
The largest amount of quartz is contained in igneous rocks, in particular in so-called granitoids, granites and related rocks. When one talks about the Earth's crust ...
Minerals, Rocks & Rock Forming Processes
This diagram shows the main groups of igneous rocks, their main mineral constituents and their intrusive (cooling in the crust) and extrusive (cooling as lava flow ...
Description of Deposit - nvp-pgf.org
Information. CHARACTERISTICS OF THE DEPOSIT. The geology of the deposit can be summarized in a sequence of volcano-sedimentary rocks crossed by a felsic intrusive ...