Which of the following metals is NOT classified as a mazit metal?

The classification of metals as mazit metals pertains to their density and other characteristics. Mazit metals, such as iron, nickel, and aluminium, typically have a certain density that aligns with their classification in metallurgy and material science.

Gold, on the other hand, is classified as a precious or noble metal rather than a mazit metal. It stands out due to its unique properties, such as its high resistance to corrosion, malleability, and conductivity. Additionally, gold has a higher density compared to mazit metals but is categorized separately due to its economic and aesthetic value.

When considering the density characteristics, aluminium, nickel, and iron all belong to the more common metals, thus fitting the mazit category. This distinction clarifies the classification of gold as a non-mazit metal, making it the correct answer for this question.