Identify the Mineral on the basis of the following characteristics relating to it : I. It is usually a greenish crystal. II. It is often found in basaltic rocks. II. Magnesium, iron and silica are its major elements. Select the answer using the code given below :

The mineral described is Olivine. According to the provided text, the main elements of olivine are magnesium, iron, and silica [1]. It is characterized by a distinctive olive-green to deep bottle-green color and typically appears as a greenish crystal [1]. Olivine is a primary rock-forming mineral in mafic and ultramafic igneous rocks, being frequently found in basaltic rocks, gabbro, and peridotite [1]. While pyroxene also contains magnesium, iron, and silica, it additionally includes calcium and aluminum and is often found in meteorites or appears black [1]. Amphibolite is a metamorphic rock rather than a single mineral. Feldspar is primarily composed of aluminum silicates with potassium, sodium, or calcium and rarely exhibits a greenish color. Therefore, the combination of a greenish crystal form, basaltic occurrence, and a magnesium-iron-silica composition uniquely identifies olivine [1].

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 13: Types of Rocks & Rock Cycle > 13.5. Some Rock-Forming Minerals > p. 176