32 Anniversary Address. 



Zealand (as Dr. Hector has stated), as well as in Otago, i.e., not 

 in lodes but as a member of drift deposits, there is a sort of union 

 between these and other regions in which the diamond is found. 

 Drift or alluvial Cinnabar is not less remarkable than drift 

 diamonds ; and I believe at present no lode has been detected. 



In California Cinnabar is said to be brought up by Solfatara 

 action. {Phillips in PJiil. Mag., Dec. 186S. p. 431.) It may, 

 therefore, be that the Cudgegong mineral is due to the action of 

 former hot springs. The account given by Mr. A. Phillips 

 respecting the " Chemical G-eology of the G-old Pields of 

 California " in the paper cited above, justifies the further inference 

 that Silicated waters may also have operated in coating and 

 cementing pebbles and fragments of rocks at Cudgegong as they 

 have done in California. He even shows, that quartz veins 

 holding gold and coloured by pyrites, as well as auriferous pyrites 

 itself, have been formed ia recent times by the action of aqueous 

 solutions. 



DIAMOjS'DS TS BORNEO AlfD AFEICA. 



There are but two other countries to which I need refer, 

 Borneo and Africa. 



In the southern ravines of the Eotos Borneo chain, which is 

 composed of Serpentine, Diorite, and G-abbro, which run north 

 and south, there is a deposit of red clay with fragments of quartz^ 

 in which spangles of gold, magnetic iron, platinum, and also 

 osmium and iridium are met with, the whole reposing on 

 Serpentine. In this clay, on the loestern slopes, diamonds are 

 found over fragments of Sienite and Diorite, and with the ores 

 above-named. Black quartz with pyrites and plates of platinum 

 are there the indications of diamond and, according to M. Louis 

 Horner, tliis quartz belongs to the Serpentine. {8ee d'Archiac^ 

 ii., 333.) 



So varied, yet, to some extent, so consistent with each other, 

 are facts connected with the history of the diamond. That its 

 mode of production in all countries may have been the same is 

 very probable ; but that origin, it must be said, obtains little 

 illustration from the various geological conditions with which it 

 is associated. Perhaps this very variety, whilst setting dogmatism 

 at defiance, may serve as encouragement to the close observation 

 of practical prospectors. 



