One of the holy grails of rare old classics from Europe is this style of Hauerite crystal: This is an equant, well formed, dodecahedral, brownish gray, crystal of Hauerite, an uncommon manganese sulfide. It is from the collection of my own mentor from my earliest years as a collector in the early 1980s, Carlton Davis of Columbus, Ohio. His competitive thumbnail collection was known all over the US for superb rarities.