Mining Engineering Board Exam Practice 2025 – Complete Prep Guide

Hematite is recognized for its distinct deep red color, which makes it easily identifiable in the field and in various applications. The mineral is primarily composed of iron oxide (Fe2O3), and its reddish hue arises due to the way it interacts with light. Hematite has a metallic luster when polished, but it can also appear dull or earthy in unpolished forms. This strong coloration is particularly prominent in powdered form, which is why it is often used as a pigment.

In contrast, goethite, while also an iron oxide, typically presents a brownish color. Plagioclase is a feldspar mineral that can vary widely in color but is not characterized by red hues. Bauxite, primarily composed of aluminum minerals, does not have the same iron and oxygen composition and tends to be earthy in appearance. Therefore, the unique composition and color of hematite make it the correct answer regarding the mineral formed from iron and oxygen that is recognized for its deep red color.