下列哪一种是单元素矿物______

A、<span style="font-family: 宋体;">石英&nbsp;</span>

B、<span style="font-family: 宋体;">斜长石 &nbsp;</span>

C、<span style="font-family: 宋体;">黑云母</span>

D、<span style="font-family: 宋体;">金刚石</span>