What does gneiss come from

Shale becomes slate , then phyllite, then schist, then gneiss. Each of these steps is gradual, as the stone slowly changes in response to the conditions it experiences. Photo courteys of M S International.

Regardless of its geologic parent rock, gneiss is near the end of the metamorphic road. Heat it further and it begins to melt. The mineral quartz will melt first. Another delicious food analogy applies here. The beginning of the melting process is just like a chocolate chip cookie left in a warm car. The chocolate chips will melt long before the rest of the cookie does.

In gneiss, you can often see fluid-looking pockets of quartz that were melted while the rest of the rock remained solid.

These basement rocks are over a billion years old and, just like the basement of your house, they are the foundation for the layers above. Newer stones pile up on top of the basement. But sometimes those newer layers get scraped away by erosion, and the older layers get heaved upward by mountain building.

Behold, the basement sticks out at the surface. One of the fun things about natural stone is the huge range of aesthetics that are expressed in stone. Gneiss is no exception; it comes in many variations, and can appeal to many different styles and tastes. While all gneiss is striped or banded, the bands can be straight, gently wavy, or chaotic. The colors can be mostly dark, or mostly light. The stone can be black and white, or black and pink, or black and gold, or nearly any combination thereof.

Interesting minerals like garnets dark pink, round specks or kyanite blue, elongated crystals can liven up the usual combo of minerals. Note that a stone of a given name can have different patterns depending on which direction it is cut and which part of the quarry it is from.

Viscount White, for example, can be serene or vivid. Gneiss is a terrific stone for many purposes. It can be easily split into thin, flakey pieces. Schists often have a high luster they are very shiny due to large crystals within the rock. Department of Earth, Atmospheric, and Planetary Sciences. Part of the EASP Geology Walk Gneiss is a metamorphic rock formed by changing schist, granite, or volcanic rocks through intense heat and pressure.

Gneiss Updated Thursday, 28th September A brief description of the nature of gneiss. Copyright: The Open University How was it formed? Get closer to geology. Geology toolkit Discover the unique landscape of the British Isles with our interactive Geology Toolkit, featuring a geology timeline, rock analyser, rock cycle, landscape features and safety tips.

Take part now Geology toolkit. Activity Level: 1 Introductory. Copyright information. Publication details Originally published : Wednesday, 27th September Last updated on : Thursday, 28th September Be the first to post a comment Leave a comment.

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