Roger Parramore is one of the stalwarts of the borosilicate glass scene, having worked as an artist and advancer of the industry for 40 years or so at this point, including advancing the boro color palette with his work in color mixing and creation. Well known for his sculptural form, he occasionally made a vortex marble here and there, and each one is a sweet slice of history. He has sometimes been credited as the originator of the vortex marble, and makes this claim himself, but when the subject is argued, it all depends on whether you consider his vortices a true vortex or not, since they don't have the same depth as those done by Kevin O'Grady, who is generally considered the father of the vortex. Regardless, Roger pushed the boundaries with his design and at the very least incubated the concept, probably coming up with the idea in the same time frame as Kevin, but in a different place, and thus these marbles of his are all very historical in nature. All of his marbles I know of, come from the late 90's and early 2000's.