This is an exceptional specimen of the arsenolamprite, the rare orthorhombic dimorph of arsenic. Arsenolamprite can occur as massive material, in foliated masses or in radiating aggregates of plates. This arsenolamprite exhibits super radiating structure, and at one end is accompanied by a dull dark grey concave aggregate of arsenic. From the Tracy Kimmel collection – Tracy built a superb suite of arsenic-bearing minerals. Tracy acquired it from John Betts (label included), who acquired it from Georg Gebhard (label included).