250 Geology of the Neilgherries. [No. 12, new series. 



so much iron that several of the peas will attach to each other in 

 a string depending from the magnet. 



11. Red iron glance in pyramidal concretions. 



12. Variety of reddle resembling rouge (undescribed.) Has a 

 red streak and reddens paper like red chalk. Is very soft and 

 easily shaped by the knife. Structure lamellar, and easily sepa- 

 rated into thin plates. Lustre shining. Becomes black and me- 

 tallic after roasting when it is taken up by the magnet. Is a com- 

 bination of iron, oxygen, water-silica, and alumina. 



13. Sulphuret of iron three varieties. 



Var. 1st. Color different shades of grey. Dull, but fractured 

 surfaces present a" white metallic lustre. 



In the matrass gives off fumes which possess the odour of sul- 

 phur, and sublime on the neck of the tube. The result after 

 roasting is raised by the magnet. Somewhat resembles white py- 

 rites. Occurs in a rock of green syenite accompanied by the fol- 

 lowing — 



Var. 2nd. Externally resembles sulphur ; of a yellow color, 

 very brittle. When rubbed between the fingers leaves a sulphur- 

 ous smell. Roasted it evolves sulphur and leaves a metallic scoria 

 acted on by the magnet. 



Var. 3rd. Investing the foregoing which it resembles in every 

 respect except color which is a greenish brown. After very care- 

 ful examination I could detect no arsenic in any of the foregoing 

 sulphurets. 



14. A green iron ore of which I can find no description in the 

 works of the English and German mineralogists. It bears a con- 

 siderable affinity to those varieties of talc described by Gruner and 

 Vauq as containing 25 per cent, of oxide of iron. Has a shining 

 pearly lustre. Color a beautiful apple green changing according 

 to the position the mineral is held in. Structure micaceous. Oc- 

 curs in flat hexagonal prisms, the angles of which are obliterated 

 and amorphous. Is soft and unctuous. No action takes place in 

 muriatic acid, though a feeble effervesence is perceptible when 

 the mineral in powder is immersed in sulphuric acid. Gives of 

 water in the bulb tube. After submission to the reducing flame 



