51 
The presence of traces of phosphoric oxide (previously observed in 
similar minerals) and of ferrous oxide is doubtless to be ascribed 
to the co-existence of an isomorplious mineral of the Hamlinite or 
Beudantite type, viz. : — 
2 RO . 3R 2 0 3 . 2P 2 0 5 . 7H 2 0 Hamlinite Type. 
2RO. 3JR 2 0 8 . 2S0 3 . P 2 0 5 . 6H 2 0 Beudantite Type. 
The molecular weight and molecular volume for the Kundip 
mineral and other minerals of the group are: — 
Molecular 
Weight. 
Specific 
Gravity. 
Molecular 
Volume. 
Natrojarosite, Kundip 
971 5 
3 11 
312-3 
Natro jarosite, pure ... 
969-4 
(3-10) 
(312-4)* 
Jarosite 
1001-6 
3-20 
313-0 
Alunite 
829-2 
2-66 
311-8 
* Assumed, being - mean of figures for Jarosite, Aluuite, and the Kundip m neral. 
From this figure the specific gravity of pure Natro jarosite, unknown in nature, is 
calculated to be 310. 
Kundip Natro jarosite is insoluble in water. Some of the finely 
powdered mineral was shaken with a little cold water to dissolve the 
associated salt and magnesium sulphate and then washed several 
times on a filter with small lots of water until the filtrates gave no 
reaction for chlorine. Subsequent treatment with cold water 
yielded filtrates giving no reaction for sulphate ion with barium 
chloride, nor for ferric ion with ammonium sulphocyanide. On 
boiling with water no change could be observed in the mineral. The 
water remained neutral in reaction to methyl orange and litmus, 
and no sulphate ion could be detected in solution. 
Cold, strong, hydrochloric acid (10 E) had no immediate effect, 
though, doubtless, complete solution would result on long continued 
digestion. On heating almost to boiling, solution was moderately 
rapid, 0.5 gramme of the mineral dissolving completely in about 
15 minutes. Dilute hydrochloric acid (5 E) acted extremely slowly 
even when boiling. 
Dilute sulphuric acid (5 E) had practically no effect even at 
boiling point. On concentrating the acid in contact with the mineral 
by evaporation on a sand bath, the powdered .mineral remained 
almost unaffected till the acid reached the strength of about 10 E, 
when solution was more rapid, and was complete just short of 
fuming point. 
The mineral is very slowly attacked by hot concentrated (16 E) 
nitric acid. 
