ADraryEESAET ADDEESS. 17 



Agate gravel is very common, and forms a striking feature in 

 the upper sources of the Yaal. This" ha,s been held by some to 

 be indicative of diamonds. 



My friend Mr. Daintree, who, I am happy to say, is now 

 Agent- Greneral in London for Queensland, was unfortunately 

 wrecked in the " Queen of the Thames," on the southern coast 

 of Africa ; but he obtained, on his overland passage to Cape 

 Town, some local information respecting the structure of the 

 country, and had an opportunity, on arriving thereat, of inspecting 

 a good collection of rocks and minerals from the diamond region. 

 In it he noticed the prevalence of an agate conglomerate from 

 the drift of the Vaal, which reminded him of a similar conglo- 

 merate at Agate Creek, on the Gilbert E-iver, which he had been 

 exploring. This being considered by him as an indication of 

 diamond, he reported his opinion to the Grovernment, and since 

 then a public reward has been oiiered for discovery of a diamond 

 field in Queensland • and, strange enough, applications have been 

 made to me by persons anxious to claim that reward, asking me 

 to point out to them likely places in which to find the gems. 

 That agates may occur in a diamond field wherein are evidences 

 of the existence of vesicular traps is far from imlikely ; and 

 at Louee, not far from Cudgegong, such conglomerate also exists. 

 But agates are common enough in various places where no 

 suspicion of diamonds is acknowledged ; for instance, at the 

 back of Mount "Wingen, in this Colony, is a mass of trap in 

 which agates abound ; so they exist at Kinnoul, near Perth, in 

 Scotland ; at Oberstein, in G-ermany ; and in the rock of the 

 Giant's Causeway, in Ireland, as well as in many other parts of 

 Europe, and in America. 



But, as it appears to me, it is an inference not very probable 

 to deduce from agates, which are a silicious deposit, a connection 

 with diamond, which is pure carbon, except so far as both maybe 

 found in a district where trap eruptions have occuri'ed. And 

 "Weiss tells us that in Southern Brazil a chain of amygdaloidal 

 trap is the source of the great quantities of chalcedonies, agates, 

 c 



