There appear to be two schools of thought with respect to exactly what should be included under the term epitaxy. One of the authors (JSW) interprets the term such that it would be limited to the oriented growth of one mineral species upon a different mineral species. The other author (RPR) feels that this is too restrictive and that secondary growth of a mineral species upon itself can also be interpreted as epitaxy.
John S. White, a consulting editor of Rocks & Minerals, operates Kustos, a museum/collector consulting business.
R. Peter Richards, also a consulting editor of Rocks & Minerals, is a mineral collector with a particular interest in crystal morphology.