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The rock in the picture is rhyolite, an extrusive igneous rock. Based on its appearance, how would you classify this rock?

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The rock in the picture is rhyolite, an extrusive igneous rock. Based on its appearance-example-1

2 Answers

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Answer:

Felsic

Step-by-step explanation:

User Jaideep Dhumal
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Answer:

A. Felsic

Step-by-step explanation:

The rock would be classified as a FELSIC rock based on its appearance.

To classify a rock based on its appearance, we would rely more on the features we can observe when we look at it. Some of the features are colour and mineral grains. We can also use its feel, cleavage, and some other physical properties.

Looking at the picture, the rock is light coloured. The mineral grains also have a fine texture because the mineral boundaries cannot easily be resolved by naked eyes.

A light coloured igneous rock is said to be FELSIC with a rich composition of silica and feldspars. Mafic igneous rocks are usually dark and have low silica contents.

From the texture of the mineral grains, we know the rock is an extrusive rock. It must have formed on the surface or very close to the surface. This implies that, the minerals could not grow into larger crystals. They cooled rapidly on encountering surface temperatures.

A rock of this type is a Rhyolite. The intrusive equivalent is granite. Granite differs from Rhyolite because they have large mineral crystals. They are both felsic.

User Saber Alex
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