The mineral copper (cu) is composed entirely of copper atoms. to which mineral group does copper belong?

The correct answer is native elements.

Explanation:

Rather than the free gases found in the atmosphere of the Earth, some twenty elements are found in nature in a pure or almost in a pure form, which is known as the native elements.  

The native elements are differentiated into three families, that is, semi-metals, metals, and non-metals. The most usual native metals that are featured by basic crystal compositions form the three groups, known as the gold group, comprising silver, gold, lead, and copper.