If your specimen has well-formed crystals with sharp edges, it likely cooled slowly beneath the Earth’s surface (intrusive). Conversely, poorly-formed or unevenly-sized crystals suggest rapid cooling ...

This group consists of potassium and sodium feldspars with a monoclinic or triclinic crystal system. The alkali feldspars are significant for their presence in granite and other felsic igneous rocks.

Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive ...

Mineralogical crystallization begins in a magma at temperatures below 1300°C. then explodes as part of a volcanic eruption, the rest of the liquid will cool very quickly, creating porphyritic rock.

Visual inspection of the dark gray rock suggested that it was probably a fine-grained basaltic igneous rock formed by the crystallization of magma near the planet's surface.

Characteristics of igneous rocks These rocks are formed when magma solidifies. As the magma cools, mineral crystals will begin to grow. These crystals will grow and interlock to form a hard ...

Early scientific papers, such as "The Order of Crystallization in Igneous Rocks" in 1912 brought his talent to light. As well, Bowen was a newlywed, marrying Mary Lamont on Oct. 3, 1911.

Visual inspection of the dark gray rock suggested that it was probably a fine-grained basaltic igneous rock formed by the crystallization of magma near the planet’s surface.