The shiniest mineral is a matter of opinion and depends on what criteria you are using to define "shiniest." However, some of the most commonly cited contenders for the title include:

* Diamond: This is the hardest known natural mineral and exhibits exceptional brilliance and fire due to its high refractive index and ability to disperse light.

* Pyrite: Also known as "fool's gold," pyrite has a metallic luster that can be very bright and reflective.

* Galena: This mineral has a very high reflectivity and a lead-gray color.

Ultimately, the shiniest mineral is subjective and depends on your personal preference.