Fluorine was named after the mineral fluorite, from which it was first isolated.

Here's why:

* Fluorite is a naturally occurring mineral composed of calcium fluoride (CaF2).

* In the late 18th century, it was discovered that fluorite emitted a weak, pale green light when heated, a phenomenon known as fluorescence.

* The word fluorite itself comes from the Latin word "fluere", meaning "to flow", referencing the ease with which fluorite could be melted.

* When the element fluorine was finally isolated in 1886 by Henri Moissan, he named it after the mineral from which it originated, fluorite.

Therefore, the name Fluorine is a direct connection to the mineral from which it was derived and the characteristic fluorescence it exhibited.