Okay, that makes sense. So I guess then that the example that I posted (from Quixel) is a chart for use with the specular workflow?? (Chrome and Gold have a black albedo there)
According to this guy: http://forum.unity3d.com/threads/albedo-charts-for-pbr.276664/#post-1836486 Microsurface and metallness is engine-dependent, while Albedo and Specular color values are engine-independent - ie the albedo value for gold in one engine is the same as in any other engine. Is this really correct? Because…