Igneous rocks are classified based upon their mineral composition and _____.A.textureB.temperatureC.hardnessD.density

The classification of igneous rocks is primarily based on two main factors: their mineral composition and their texture. Texture refers to the size, shape, and arrangement of the minerals within the rock, which significantly impacts its appearance and properties.

1. Mineral Composition: This involves analyzing the types and amounts of minerals present in the rock, such as quartz, feldspar, and mica. The proportions of these minerals determine whether the rock is classified as felsic, mafic, intermediate, or ultramafic.

2. Texture: The texture of igneous rocks can be further categorized into various types based on cooling rates and environments, leading to terms like coarse-grained (phaneritic), fine-grained (aphanitic), glassy, vesicular, and more. The cooling history affects the crystal sizes; for instance, rapid cooling results in small crystals, while slow cooling allows larger crystals to form.

Considering the options presented, the correct choice to complete the statement is A. texture. Thus, igneous rocks are classified based upon their mineral composition and texture.