104 THE MINERALS OF TASMANIA. 



in a soft clay-like matrix, associated with earthy pyromor- 

 phite and cerussite. It has occurred rarely at several of 

 the Dundas silver-lead mines, and at the Magnet it has 

 been found attached to the interior of small vughs in the 

 gossan capping the ore-body. 



177. Lepidolite (Basic Fhiosilicate of Potassium, 



Lithium, and Alum,inium) . 



Commonly known as lithia mica. It usually forms coarse 

 granular masses of flexible scales, which are translucent 

 and of a purplish colour, varying to silver-white. It 

 occurs as a narrow vein or dyke between metamorphic slate 

 and an igneous rock at MtJ. Ramsay. 



178. Lepidomelane (Silicate of Iron, Aluminium, and 



Potassium,). 



A dark-coloured variety of mica, occurring in granite, 

 usually found at the contact of the plutonic and sediment- 

 ary rocks. 



Occurs at Mt. Heemskirk. Occurs in large six-sided 

 tables, occasionally 1 inch in breadth, of a black colour, 

 and highly adamantine. Transparent in very thin laminae, 

 showing a beautiful emerald-green colour. The crystals 

 for the species are remarkably fine, and well-developed. 

 They are found aggregated in association with a peculiar 

 amphibole and quartz, and evidently form portion of a 

 contact rock on the fringe of granite. 



Locality : Hampshire, near the old silver mine. 



179. Leucochalcite (Arsenate of Copper). 



A small quantity of this substance was obtained as a 

 fine fibrous coating of a milk-white colour with axinite 

 and chalcopyrite at the Colebrook, North-East Dundas. 



180. Leuchtenbergite (Basic Silicate of Magnesium and 



Aluminium). 



A chlorite poor in iron, and thus pale in colour. Only 

 detected microscopically in the variolite rock at the Magnet 

 Mine. 



181. Leucopyrite (Arsenate of Iron). 



White arsenical pyrites is not so abundant as arseno- 

 pyrite, but it is by no means a rare species. 



At North-East Dundas it is occasionally met with, and 

 at the Colebrook Mine it is the prevailing arsenical iron 



