THE AUSTRALIAN MUSEUM MAGAZINE. 



313 



.„ vi^^^* 



A portion of the etched surface of the 

 " Delegate " meteorite (siderite) show- 

 ing Widmanstaiten figures. This is 

 reproduced direct from a contact 

 print taken from the meteorite. 



The second class of meteorite is 

 known as the iron and stone meteorites, 

 or SideroUtes. As their name imphes, 

 they consist of a mixture of the nickel 

 iron alloys and one or more of the 

 silicate minerals. The " Molong "' 

 meteorite is a very interesting example 

 of this class. It was found by ]VIr. 

 John Williams on E. Farrell's farm 

 on the Molong Creek, New South 

 Wales, in August, 1912, and weighed 

 sixty five and a half pounds. Exposed 

 to the air it rapidly oxidises and 

 crumbles away, and part of it is 

 preserved in the Museum in a glass 

 vat containing kerosene. It consists 

 of rounded crystals of olivine oc- 

 cupying the interstices of a network of 

 nickel iron alloy. The Sydney Tech- 

 nical College cut this meteorite into 

 two portions, but owing to its hardness 

 ordinary metal -cutting appliances were 

 useless, and saw blades made of sheet 

 copper fed with emery and carborun- 

 dum were used ; in all it took 141 hours 



to cut through. The great majority 

 of the olivine has been fractured, but 

 by careful examination the late W. H. 

 Gilding was able to obtain a small 

 ])iece of gem quality which he cut and 

 polished. This gem is now preserved 

 in the Mining and Geological Museum, 

 Sydney. 



The next class is represented by the 

 stony meteorites or Aerolites, which 

 consist essentially of sihcate minerals 

 such as pyroxene, olivine and felspar. 

 There may be present a little nickel- 

 iron alloy. A meteorite of this class 

 was discovered by Mr. A. McCormack 

 near Einda, New South Wales, on the 

 5th June, 1912. He was engaged in 

 rabbit traj^ping when he noticed what 

 he took for a newly-formed rabbit 

 burrow ; on tracing the burrow to its 

 termination he discoveredthe meteorite. 

 It consisted of felspar, pyroxene, chrom- 

 ite and a little nickel-iron alloy. It is 

 almost certain that tiiis meteorite was 

 seen to fall on the night of Saturday, 

 25th May of the same year, when a 

 meteor was seen passing over Goulburn 

 and Crookwell, and was accompanied 

 by a loud noise which one resident 

 mistook for a passing aeroplane. 





Australites, a variety of Obsidianite, showing 

 the characteristic shapes. 



[ Photo— G. C. Clutton. 



The fourth class is represented by the 

 glassy meteorites or Obsidianites, which 

 consist entirely of glass, and are in- 

 variably small in size. These very 

 interesting objects occur in only a few 

 very wdely scattered localities — Aus- 

 tralia, Bohemia and Malaysia. It has 

 been suggested that these obsidianites 

 are of volcanic origin, but they always 

 occur in regions far removed from 

 volcanic activity, and are now generally 

 accepted as meteoric. 



