I've added one version of crystals. There's still some texturing stuff I want to figure out but they actually don't look half bad they way they are.
Wrong Texture on Crystal OBJ Model
I'm in the process of adding crystal formations to the caves and I accidentally applied the wrong texture to model. Looks kinda cool.
Converting 3D Coordinates Into Screen Space
Finally got my Matrix4 * Vec3 function working so that I can use my view and projection matrix to get a screen coordinate for a specific point in 3D space. This will be useful for dialogue boxes and clipping faces in front of the player when in 3rd person.