The hardest mineral out of calcite, talc, fluorite, and quartz is quartz.

Here's why:

* Hardness is measured on the Mohs Hardness Scale, which ranges from 1 (softest) to 10 (hardest).

* Quartz has a hardness of 7.

* Calcite has a hardness of 3.

* Fluorite has a hardness of 4.

* Talc has a hardness of 1, making it the softest mineral on the list.