Scoria igneous rock. Scorias color can range from black or dark gray to a deep reddish brown. There are two basic types. Scoria usually has a composition similar to basalt but it can also have a composition similar to andesite. Scoria is a dark colored igneous rock with abundant round bubble like cavities known as vesicles.
Intrusive igneous rocks crystallize below earths surface and the slow cooling that occurs there allows large crystals to form. Komatiite a rare extrusive igneous rock required much hotter melting temperatures to form than occur now. Scoria is a dark colored extrusive igneous rock with abundant round bubble like cavities. Scoria is a highly vesicular dark colored volcanic rock that may or may not contain crystals phenocrysts.
It is usually dark colored and has a mafic composition. Scoria is a volcanic igneous rock. It is typically dark in color generally dark brown black or purplish red and basaltic or andesitic in composition. Scoria is an igneous rock that is dark colored with abundant bubble like cavities called vesicles.
It is commonly composed of approximately 50 silica and 10 calcium oxide with lesser contents of potash and soda. In an extrusive rock the crystals are usually so fined grained that they are not visible by the naked eye. It ranges in color from black or dark gray to deep reddish brown. Examples of extrusive igneous rocks are basalt andesite rhyolite dacite obsidian pumice and scoria.
Igneous rocks are formed from the solidification of molten rock material. There are two basic types. It is difficult to say for sure whether it is a rock type or not. An intrusive igneous rock has larger crystals than an extrusive igneous rock.