OCCURRENCE OF BEEKITE IN N. S. WALES — ETHERIDGE, 
75 
common and precious opal, and “ orbicular silica ” or Beekite. 
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.’* * * § 
Beekite , 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, f who 
gives the best 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, Murrumbidgee. If my memory 
does not deceive me, there are also traces of the mineral on the 
chalcedonically replaced Brachiopoda from the Permo-Carboniferous 
rocks of Point Puer, Tasmania, in the Natural History Museum, 
London. 
Prof. A. II. Church, J 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 W ales, etc., with map. (8vo. London, 1888). 
t Glossary of Mineralogy, 1861, p. 39. 
X Journ. Chem. Soc., 1861, XV., p. 109. 
§ Journ. Chem. Soc., 1863, XVI., p. 31. 
