OCCURRENCE OF BEEKITE IN N. S. "WALE3 — ETHERIDQE. 75 



common and precious opal, and " orbicular silica " or Beehite. 

 We have in the Collection a valve of a Tertiary Pelecypod from 

 Port Fairy, in Victoria, completely converted into iron-pyrites ; 

 the Collection of the Department of Mines possesses some ex- 

 cellent specimens of conversion into the two opals from the 

 Western Opal-fields ; whilst in the present communication it is 

 intended to deal with certain corals, showing the entire structure 

 replaced by orbicular silica, or Beekite, a mineral not recorded in 

 Prof. A. Liversidge's ' Minerals of New South Wales.'* 



Beehite, strictly speaking, is not a true mineral species, but a 

 chalcedonic variety of silica, replacing the carbonate of lime of 

 fossil organic remains by secondary silicification. Bristow,! who 

 gives the l)est description, says that in the New Red Conglomerate 

 of Devonshire (Eng.), it occurs as rounded masses from half to 

 one inch, but sometimes from three to six inches. The surface 

 consists of chalcedony arranged in tubercles from the size of a 

 pin's head to that of a pea, each of which is surrounded by one 

 or more rings, producing a more or less rosette-like appearance. 

 Amongst other localities, Bristow incidentally mentions its occur- 

 rence in India, and " in Australia, in Triassic Conglomerates," 

 but I am not acquainted with the source of his information as to 

 the last-named occurrence. 



I have met with Beekite on a Strophalosia from the Permo- 

 Carboniferous of Bingera, Co. Murchison, in the Department of 

 Mines Collection, and plentifully on Siluro-Devonian Corals in 

 the black limestone of Cave Flat, Murruiubidgee. If my memory 

 does not deceive me, there are also traces of the mineral on the 

 chalcedonically replaced Brachiopodafrom the Permo-Carboniferous 

 rocks of Point Puer, Tasmania, in the Natural History Museum, 

 London. 



Prof. A. H. Church,! who has to a certain extent artifically 

 simulated Beekite in the Laboratory, speaks of it as " a curious 

 silicified substance, at once a mineral and a fossil," presenting 

 itself under such a variety of aspects as to baffle description, so 

 far as regards its physical features. Its chemical composition, 

 however, is more constant, the original constituents having 

 become " so modified in constitution as to contain on an average 

 no less than 92 per cent, of silica," a small but variable quantity 

 of lime remaining, but more in the form of silicate than carbonate. 

 Prof. Church's theory, expressed in his own words,§ is " that 

 water charged with carbonic acid and silica removed the carbonate 



* The Minerals of New South Wales, etc., with map. (8vo. London, 1888). 

 t Glossary of Mineralogy, 1861, p. 39. 

 J Journ. Cham. Soc, 1861, XV., p. 109. 

 § Journ. Chem. Soc, 1863, XVI., p. 31. 



