I'm looking at the mineral feldspar.

if it does, how does light travel through feldspars crystal structure? can someone explain feldspar crystal optics to me?

No

Explanation:

Feldspar is a rock-forming silicate mineral, that makes up 50% of the rock mass of the earth. Found in all igneous and metamorphic rock systems. Being an important component of gabbro and basalt that are primary rocks on the earth and made of this mineral. Feldspar is a group of minerals composition made Silicon and aluminum, they have perfect cleavage and 90 degrees of consistent hardness. Its commonly found in stone like Quads. They are found in various colors of light such as orange, pink, white, etc Having a hardness of 6 on moho scale.