marble - metamorphic rock that cannot fall into these categories. Diorite is usually grey to dark grey in colour, but it can also be black or bluish-grey, and frequently has a greenish cast. Intermediate rocks are composed of the minerals amphibole and feldspar and contain a combination of light and dark minerals. What rock from the chart is both MAFIC and INTRUSIVE. Mafic Rocks and Rhyolite We have granite, which is intrusive felsic, diorite, which is intrusive intermediate, and andesite, which is extrusive intermediate. Step 1: Composition Texture Felsic Intermediate Mafic Aphanitic Phaneritic Porphyritic Pegmatitic Vesicular Pyroclastic Glassy Figure 6.12 Igneous Rock Lab Chart. These rocks form a series that varies in composition, from felsic to mafic because of an increasing fraction of iron+magnesium rich minerals that darkens the tone. Na2O — 3.59 The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite. It is contrasted with mafic rocks, which are relatively richer in magnesium and iron.Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. Intrusive Igneous Rocks 2. Additionally, they contain somewhat more gas than do the mafic magmas, but not quite as much as the felsic magmas (see below). Geology Victoria Map 1553A. 139 HOLIC Lab #6-Igneous Rock Samples Red Granite Rhyolite Diorite Gabbro Gray Granite Obsidian Andesite Basalt Rhyolite Tuff Pumice Hannukainen, Finland. It is used as a dimension and building stone, but not very widely because of limited supply. Why not complete the set of stone variants with rhyolite, which is extrusive felsic, gabbro, which is intrusive mafic, and basalt, which is extrusive mafic? basalt. Its volcanic (fine-grained) analogue is andesite. Remember that green (even light green) is considered to be a “dark” color. Intermediate: refers to igneous rocks where the proportions of light and dark minerals are roughly equal. Mafic: refers to igneous rocks that are dominated by dark Here are other interesting facts about diorite to notice: Facts about Diorite 1: the difference of diorite and gabbro. It is visibly crystalline and usually has a granular texture (composed of roughly equally sized crystals) although the appearance may vary widely. This diorite is more salt than pepper, but it appears to have less than 10% quartz and no K-feldspar. Its vesicular structure makes it light enough to float on water. This sample has some resemblance, but contains too much quartz. 20% 50% 70% 100%. Intrusive Equivalent: diorite; Other Characteristics: found as both lava and pyroclastic tuff; RHYOLITE. Mafic and felsic dikes that intrude Beehive Diorite recrystallised under amphibolite and then greenschist facies conditions. Diorites may be associated with either granite or gabbro intrusions, into which they may subtly merge. Rhyolite is an extrusive felsic (silicic) volcanic rock. Mafic Rock. Basalt - Mafic. Its vesicular structure makes it light enough to float on water. It is distinguished from gabbro on the basis of the composition of the plagioclase species; the plagioclase in diorite is richer in sodiuma… Compilations of many rock analyses show that rhyolite and granite are felsic, with an average silica content of about 72 percent; syenite, diorite, and monzonite are intermediate, with an average silica content of 59 percent; gabbro and basalt are mafic, with an average silica content of 48 percent; and peridotite is an ultramafic rock, with an average of 41 percent silica. Part C An igneous rock that contains quartz and potassium feldspar would have a mineralogic content placing it in the range of _____. The color index of an igneous rock is a measure of the ratio of dark colored, or mafic, minerals to light colored, or felsic, minerals. In geology, felsic is an adjective describing igneous rocks that are relatively rich in elements that form feldspar and quartz. MgO — 3.77 Diorite may not be easy to distinguish from similar rocks. Aa And Pahoehoe Lava 10. diorite: mafic: Ca-plagioclase, pyroxene, olivine, amphibole: gabbro: ... glass (may contain a few minerals typical of felsic rocks) pumice: mafic: glass (may contain a few mineral typical of mafic rocks) scoria: Note: Basalt with fewer holes, known as vesicles, is called vesicular basalt. Granodiorite and tonalite are granitoids that contain more than 20% quartz. Subsequently, one may also ask, is granite mafic felsic or intermediate? Posted on August 31, 2014 by triplejunction. Felsic to Mafic: Pumice: Vesicular: glass (may contain a few minerals typical of felsic rocks) Felsic: Rhyolite, ... such as granite, gabbro, or diorite. This diorite is closer to the classic balance of mafic and felsic minerals (salt-and-pepper appearance). The extrusive volcanic equivalent rock type is andesite. Diorite would have roughly equal amounts of these minerals. Felsic, intermediate and mafic igneous rocks differ in their mineral composition. FeO — 4.99 Uralite is a name given to secondary hornblende (or actinolite) phenocrysts. When olivine and more iron-rich augite are present, the rock grades into ferrodiorite, which is transitional to gabbro. The grey or dark grey diorite is very common to spot in the world. Some diorites contain biotite as well as hornblende, and some contain up to 10% quartz. Subsequently, one may also ask, is granite mafic felsic or intermediate? Conglomerate - Clastic Sedimentary. Diorite may form larger plutons, but it often forms smaller magma bodies like sills, dikes and stocks. 2. 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