Pronounced u-art, and short for universal asynchronous receiver-transmitter, the UART is a computer component that handles asynchronous serial communication. Every computer contains a UART to manage the serial ports, and some internal modems have their own UART.
1 Color. 2  Color of a rock depends on the minerals present and on their grain size. 3  Generally, rocks that contain lots of feldspar and quartz are light colored, and rocks that contain lots of pyroxenes, olivines, and amphiboles (ferromagnesium minerals) are dark colored.
These minerals, known as index minerals, include sillimanite, kyanite, staurolite, andalusite, and some garnet. Other minerals, such as olivines, pyroxenes, amphiboles, micas, feldspars, and quartz, may be found in metamorphic rocks, but are not necessarily the result of the process of metamorphism. These minerals formed during the crystallization of igneous rocks.