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SALTS OF THE ALKALIES, ALKALINE EARTHS, AND ALUMINA. 

 Halite {Coiwnon Salt). 

 This mineral occurs iu beds near and on the shores of the 

 various salt lakes of the colony, and Tate reports it in the form 

 of an efflorescence on the faces of the cliffs of the Eiver 

 Murray. 



Barite {Barytes — Heavy Spar') 

 Occurs at the Wheal Coglin Mine, Eapid Bay ; at Apoinga ; 

 also at the Burra Burra, Grreat Grladstone, and E-hondda Mines. 

 Selwyn reports its occurrence at the Emu Flat Copper Mine, 

 and IJlrich at the Blinman Mine. 



Celestite {Gelestine), 

 I haye met with this mineral in the form of radiated crystal- 

 line nodules in a bed of clay, Hundred of AYallaroo. 



Gypsum. 

 The crystallised variety of this mineral (Selenite) is fre- 

 quently met with in the form of isolated lenticular-shaped 

 crystals imbedded in the mud of the salt lakes, notably those 

 of Southern Yorke Peninsula. It is also found massive in the 

 salt lakes. Gypsum also occurs in the following localities : — 

 Wallaroo Mine, Hummocks Eauge, Kanyaka, Kapunda; near 

 Point Eiley, Yorke Peninsula ; on the Wirryalpa Eun, 

 Central Australia ; and fine specimens of the fibrous variety 

 (Satin Spar) occur in the Stuart Eange, Central Australia. 

 Professor Tate reports its occurrence at the Lady Alice Mine 

 and cliffs of the Eiver Murray, and with red ochre near the 

 springs at the Peake, Central Australia ; also in a curious rock- 

 form composed of slightly coherent grains on the north-eastern 

 shore of Lake Alexandrina. Ulrich noticed it in the form of 

 veins at the Beltana Mine, and Burr mentions it as occurring 

 at Brighton. 



Calcite. 

 This mineral, in one or other of its numerous rock forms, is of 

 very common occurrence in the colony, although good crystallised 

 specimens are not as frequent as might be expected. Pinely 

 crystallised specimens have, however, been obtained from the 

 AVallaroo Mines. The most noticeable of these are in the 

 form of six-sided prismatic crystals, formed by a very acute 

 rhombohedron, terminated by an obtuse rhombohedron of the 

 opposite sign ; another form, which is almost unique, being a 

 triangular prism with a rhombohedral termination. A very flat 

 lenticular form is also found. It also occurs coarsely crystal- 

 line and milk-white with the copper ore in the above-men- 

 tioned and neighbouring mines. 



