48 Transactions of the 



When these questions come to be worked out, it is of course 

 possible that an unfavourable result may follow in each case, and 

 we thus have a good illustration of the great risk of mining 

 operations, which causes mines to be such dangerous and yet such 

 tempting investments to persons of a speculative turn of mind. 



We will now pass on to the character of the ore found. This 

 consists of the sesquioxide of iron, of which there are three kinds: 



1. Anhydrous sesquioxide or red haematite, FcoOs. 



2. Gcethite, TeAHA 



3. Limonite or brown htematite, Fe^OaSHjO. 

 These are distinguished as follows : — 



1. Red hsematite ; streak cherry-red or reddish-brown ; crystalline; 

 gives off no water when heated in glass tube ; infusible ; colour 

 dark steel-grey or iron-black ; of earthy varieties, red, including 

 red ochre, 



2. Gcethite ; streak brownish-yellow ; gives off a little water 

 when heated ; generally crystallised in prisms, or flat tables, 

 or fibrous; colour reddish and blackish brown, yellowish by 

 reflected light, often blood-red by transmitted light. Before 

 blowpipe blackens and becomes magnetic, forming FesO^; thin 

 splinters fusible to black magnetic glass. 



3. Limonite ; streak yellowish-brown ; gives off water when 

 heated ; generally mammillated, botryoidal, or stalactitic, aUo 

 compact or earthy ; colour various shades of brown, from 

 yellowish-brown to nearly black ; before the blowpipe, as 

 gcethite. The earthy varieties form yellow and brown ochre. 

 The gcethite is found in very insignificant quantities incrusting 

 the other two oxides. 



By far the larger portion of the ore here in the three solid 

 beds consists of limonite. The clayey ore is a mixture of yellow 

 and red ochre, and is of no very definite composition. The red 

 hsematite is generally found in the interior of the lumjis of ore, 

 while the hydrated oxide forms a crust of greater or less thickness, 

 being sometimes quite thin. The only varieties of red haematite 

 I have yet seen here are the compact and the red ochre. 



The gcethite occurs crystallised in prisms and tables, coating 

 stalactites of limonite, and in cavities of red haematite or of the 

 sandy rock. 



The varieties of limonite are — 



1. Compact. 2. Fine stalactites. 3. Mammillated. 



4. Botryoidal. 5. Fibrous crusts. 6. Yellow ochre. 



The forms assumed by the stalactitic limonite are very much 

 varied, sometimes long and regularly tapering, sometimes short 

 and irregular, or broad and smooth, or in small pear-shaped forms ; 



