Which of the following minerals is a ferromagnesian silicate? Muscovite Quartz Hornblende Orthoclase

Ferromagnesian silicates are a group of minerals that contain iron and magnesium. They are typically dark in color and have a high specific gravity. Among the options provided:<br />1. Muscovite is a type of mica and is not a ferromagnesian silicate.<br />2. Quartz is a silicate mineral but does not contain iron or magnesium, so it is not a ferromagnesian silicate.<br />3. Hornblende is a ferromagnesian silicate, containing iron and magnesium.<br />4. Orthoclase is a type of feldspar and is not a ferromagnesian silicate.<br />Therefore, the correct answer is Hornblende (Option C).