What Minerals Are Isotropic

Minerals that are isotropic include halides such as fluorite and halite, some of the oxides such as the spinels, and some silicates including members of the garnet group and the sodalite group of feldspathoids.

Is quartz anisotropic or isotropic?

Quartz crystals are birefringent, so they exhibit optical anisotropy.

Is garnet isotropic?

Garnet is one of the few common isotropic minerals. It is generally colorless or has a pale tinge, often irregularly fractured, and has high relief.