THE MINERALOGY OF SCOTLAND. 



355 



3. From North Quin Geo, Hillswick. Epidote occurs here filling a small vein. It 

 forms stellate groups of rich green crystals over an inch in length. 

 The analysis on T503 grammes yielded — 



Silica, ...... 



36T27 



Alumina, ..... 



20-574 



Ferric Oxide, .... 



14-921 



Manganous Oxide, . 



•306 



Lime, ...... 



23-025 



Magnesia, ..... 



•306 



Water, 



4-568 



99-827 



Insoluble silica, 7'734 per cent. 



The ferric oxide is to the alumina as 1 to 2. 



4. From Delnabo, Glen Gairn, Aberdeenshire. Out of the old limestone quarry. 

 ! t occurs imbedded in green prehnite, in radiated crystals of a pale green colour. 

 On 1'501 grammes — 



Silica, ...... 



38-374 



Alumina, ..... 



26-087 



Ferric Oxide, .... 



10-388 



Manganous Oxide, .... 



•738 



Lime, 



21-647 



Magnesia, 



•239 



Water, 



2-441 



99-914 



Insoluble silica, 7*812 per cent. 



The ferric oxide is to the alumina as 1 to 4. 



WITHAMITE. 



This red variety has been found only at one spot. This is a projecting spur of 

 nygdaloidal felspathic porphyry, which touches the road through Glencoe upon its 

 3rth side, about three miles above the turn of the glen. The epidote occurs in the 

 btle druses, very rarely in bright green crystals. It is then associated with byssolite 

 id chlorite. Much more frequently it occurs in the red modification. It forms very 

 inute acicular crystals of a brilliant blood-red colour. These crystals radiate from the 

 ies of the druses, a narrow layer of a milky saussurite-like substance sometimes 

 tervening. The crystals are red and yellow respectively in two directions, at right 

 ugles to one another (MacKnight and Brewster). Minute specks of quartz sometimes 

 <cur. 



On account of the extremely minute quantity in which this substance is found, the 

 l.riiying of the sample analysed was executed with extreme care. 



