Area: 0.43 hectares.
A Geological Conservation Review site.
The site is in South Devon Area of Outstanding Natural Beauty.
Description and Reasons for Notification:
At Wheal Emily a vein carrying antimony-lead mineralisation is associated with a north-west to south-east trending fault zone which cuts strata of Lower Devonian age.
The underground workings are important in clearly demonstrating the geological setting of the mineralisation although the amount of in situ ore now to be seen is limited. The ores are a complex intergrowth of jamesonite with subsidiary galena and copper- and lead-bearing complex sulphides (bournonite, boulangerite, semseyite, and meneghinite). The best specimens are to be found in the spoil heaps adjacent to the old workings. Some of the complex sulphides are known from only one or two other localities in Britain.
The Wheal Emily mineralisation has been long considered to be an isolated occurrence. The recent discovery, however, of nearby stratiform orebodies, associated with volcanic rocks and faulting, puts the mineralisation into a quite new context and underlines the importance of the site to our understanding of antimony mineralisation. The site is of the highest research interest.