Table of Contents
What are the sizes shapes and positions of minerals of a rock?
ROCKS & MINERALS VOCABULARY
| A | B |
|---|---|
| texture | Quality of a rock that is based on the size, shape, and position of the rocks grains |
| Composition | The chemical makeup of a rock; describes either the minerals or materials in a rock |
| Intrusive Igneous Rock | Rock formed from the cooling and solidification of magma under Earth’s surface |
What determines the grain shape of a rock?
Rocks are made of minerals and other materials. What determines the grain shape of a rock, such as granite? The shape of the rock’s crystals.
What is the shape of the rocks?
Rocks can be round, angular, rectangular, square, triangular, heart shaped, or irregularly shaped.
What is it made of basalt?
Basalt is a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene minerals. It most commonly forms as an extrusive rock, such as a lava flow, but can also form in small intrusive bodies, such as an igneous dike or a thin sill. It has a composition similar to gabbro.
Are rocks homogeneous or heterogeneous?
Rock as a natural material is heterogeneous. Rock material consists of minerals, crystals, cement, grains, and microcracks.
What is the shape of grains?
Krumbein (1941) found that an ellipsoid generally provides an acceptable approximation of actual grain shape, so the results of Kellerhals et al. appear to be robust. However, most deposits of clastic grains possess some preferred fabric, which would render the result invalid.
What are the texture of rock?
The texture of a rock is the size, shape, and arrangement of the grains (for sedimentary rocks) or crystals (for igneous and metamorphic rocks). Also of importance are the rock’s extent of homogeneity (i.e., uniformity of composition throughout) and the degree of isotropy.