Their origin and formation. 123 



similar protuberance in the same position was noticed. 

 Again the cold chisel was resorted to, and again 

 a large Pearl was found. This time, however, 

 although perfectly round and the size of a large 

 solitaire marble, it had come within reach of the 

 advancing decay of the shell ; one third of an inch 

 was rotten, and after its weight was reduced from 

 84 to 45 grains, a round slate coloured Pearl was 

 obtained, but of little value. A year previously this 

 Pearl might probably have been found perfect, and 

 have been worth say from ;^20oo to ;^3000. It 

 is worthy of remark that when decay reaches the 

 lower point of an embedded Pearl, it spreads 

 upwards around the Pearl, aided apparently by the 

 upward tendency of the layers of the blister, and 

 eats into it, at an almost equal rate all round. 



In 1882 the "Harriet" was fortunate enough 

 to find a Pearl, weighing 103 grains, within an 

 enormous blister. It was a beautiful bouton, of fine 

 colour on the top, but somewhat chalky beneath, 

 owing to the contact of salt water admitted by a 

 "borer," that had chanced to pierce the shell just 

 at this spot, and had penetrated nearly \ of an 

 inch into the Pearl. 



In 1885, the "Ivy" found a Pearl in the lips 

 of a small-sized shell, whilst fishing in Exmouth Gulf. 



