AN UPDATE ON 35 YEARS OF BLOSS' TURNING POINT

Thirty five years ago Don Bloss gave his MSA Presidential Address: “The spindle stage: A turning point for optical crystallography.” I started my graduate studies shortly after that and my own “turning.” However, prior to the refinement of the spindle stage methods, Don already had an illustrative academic career. He was editor of the American Mineralogist (1972 to 1975) and probably best known for his two books “An Introduction to the Methods of Optical Crystallography” (1961), followed by “Crystallography and Crystal Chemistry” (1971); revised versions of both are available from MSA, with royalties going into the newly created “Bloss Optical Crystallography Fund.” His teaching skills earned him the rank of Alumni Distinguished Professor at Virginia Tech. Don was also an active researcher publishing papers as varied as “Observations on some Yellowstone Geysers,” with Tom Barth to “Cleavage in Quartz,” with G.V. Gibbs, one of his earliest graduate students. And yes, quartz does have cleavage, and what a unique way they proved it! Refer to Don’s memoirs, just published by MSA, for interesting background stories on the above papers as well as other aspects of Don’s life.

Returning to the past 35 years, Don stayed on his one-book-per-decade pace with “The Spindle Stage: Principles and Practice” (1981). The optical properties of several minerals (e.g., cordierite, alkali feldspars, and andalusite) were unraveled in a short time by Don and his co-workers during this time. Interestingly, we predicted that andalusite, an orthorhombic mineral could appear isotropic with certain compositions. And when isotropic andalusite was found in nature, it was also pleochroic! We worked to incorporate the spindle stage into other analytical equipment – basically using it to study the orientational dependence of the physical properties of minerals. For example, simplifying the task of determining the optical orientation of minerals, to examine the morphology of the particles by combined optical and electron beam studies, understanding how XANEs spectra vary with orientation – and no doubt there’s more “turning” to come.

And to end with a quote from Thomas Armbruster’s (who was a post-doc with Don) 2008 MSA Dana Medal acceptance paper: “I owe my scientific career to him.” And the “him” is Don Bloss. Needless to say, me too!