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says it is imbedded in oxide of manganese ; is of a silver 

 gray colour with a metallic lustre; divergingly foliated 

 texture, somewhat malleable, and that it soils the fingers. 

 Not knowing of its being found hitherto in Great Britain, 

 we give this short account of it, and shall be glad to be 

 favoured with any specimens which may be met with here- 

 after. We describe with much pleasure the present speci- 

 men of crystallized oxide, as propitious to an expectation 

 that Great Britan nearly includes all that is essential to a 

 knowledge of mineralogy, very few genera being excepted. 



Mines have been worked in many parts of Great Britain 

 for oxide of manganese. I have some specimens from 

 Mendip Hills in Somersetshire, crystallized in small short 

 rhomboidal prisms. The one figured is crystallized in 

 elongated ones, which have striae on their sides that agree 

 with the fracture. We also find the apex show signs of a 

 diedral ortetraedral summit. 



The upper right hand figure is nearly the natural appear- 

 ance and size of the specimen; the prisms standing irregu- 

 larly and joining near the base, w T here they stand upon sul- 

 phate of barytes, Sec. The gangue is a sort of stratified 

 micaceous grit, through a stratum of which it runs in veins. 

 In a mass sent me from Aberdeen, the manganese includes 

 crystallized sulphate of barytes, &c. as trap sometimes 

 .does other stones. The left hand upper figure is magni- 

 fied, and shows how irregularly the crystals stand on the 

 .mass in some parts. The left hand loltom figure shows 



