I got a lava texture from poliigon.con and noticed that there are 2 types of maps that I have never encountered. One is an "emissive" map, and one is a "mask" map. Will I need to use these maps along with the Diffuse, Gloss, Normal, and Displacement maps to improve the realism of the texture??If so, how do I properly plug these in in blender cycles
 2.79? 

Textures:https://poliigon.com/texture/2778