S86 Transactions. — Geology. 



Art. XXXIV. — On the Occurrence of Native Silver at the 



Thames Goldfield. 



By James Paek, F.G.S., Lecturer, Thames School of Mines. 

 [Read before the Auckland Institute, 2nd November, 1891.] 



The great extension of mining operations in the up-country 

 goldfields of the Hauraki Peninsula during the last few years 

 has led to the discovery of many mineral substances which 

 were not previously known to exist in New Zealand. This is 

 particularly the case with respect to silver and its combina- 

 tions, of which many rare and valuable forms have been 

 found. 



To these must now be added native silver, which has 

 recently been found by Mr. George Peel in the Nordenfeldt 

 Mine, situated on the watershed between Shellback Creek and 

 Tinkers' Gully, which falls into Tararu Creek. 



The silver occurs in an ordinary greyish-blue crystalline 

 quartz, in a 12in. vein known as the South British leader, 

 which drops into the hanging- wall of Dixon's Eeef. It is 

 found in very narrow irregular shoots running parallel with 

 the walls of the leader, in the form of thin shining scales, 

 resembling fine scales of mica, dispersed in a soft black 

 powdery substance which looks like precipitated silver, and 

 assumes a bright metallic lustre when rubbed or pressed with 

 the blade of a knife. 



Last year I drew attention to the occurrence of petzite in 

 the Nordenfeldt Mine ; and since that date pyrargyrite, the 

 antimonial sulphide of silver, has been found there in con- 

 siderable quantities, closely associated with the native silver, 

 the form of which would tend to show that it was a product 

 of the decomposition of one of these ores. A ton of quartz 

 from this leader was treated at the School of Mines experi- 

 mental plant, but the silver was found not to exist in payable 

 quantities. 



In the jurors' reports of the New Zealand Exhibition held 

 at Dunedin in 1865, page 403, Sir James Hector states that 

 silver in a native state was exhibited in small rolled fragments 

 from Wakatipu Lake Diggings. This is the only reference I 

 can find to the occurrence of native silver in New Zealand. 

 The present discovery of native silver in the Nordenfeldt Mine 

 is of great interest as being the first authenticated discovery 

 of silver in a native state in situ in New Zealand. 



The specimen of quartz containing native silver has been 

 deposited in the Auckland Museum. 



