74 JOURNAL OF THE 



OCCURRENCE OF ZIRCONIUM. 



BY F. P. VENABLE. 



Zirconium occurs principally in the form of silicate in 

 the hard, heavy mineral known as zircon. 



That this mineral was known in very early times is 

 highly probable from the number of localities where it may 

 be found and its striking physical properties. Yet it is dif- 

 ficult to assert positively that Theophrastus referred to it 

 under the name lyncurium, or Pliny under the various terms 

 chrysolithos, melichrysos and crateritis. The evidence for 

 the first is based mainly on the fact that it is spoken of as 

 a material from which to cut cameos. Theophrastus says 

 the lyncurium was used for engraved signets, was electric 

 on friction and was often amber-colored. 



Whether the ancients distinguished the zircon from other 

 minerals and knew it under any of the above names or not 

 it is certain that intagli of zircon are not at all uncommon 



among ancient gems. 



Agricola and Interpe speak of the jacinth. The first 

 mention of the Ceylonese name Jargon seems to be by 

 Cronstedt in 1758. DeLisle in 1783 writes of the "Dia- 

 mant Brut ou Jargon de Ceylon." This name Jargon was 

 long used for the colorless and yellowish and smoky zircons 

 of Ceylon in allusion to the fact that while resembling the 

 diamond in lustre they were comparatively worthless. 

 From this comes the name zircon. The colorless or only 

 slightly smoky kinds seem to have often been sold for 

 inferior diamonds. 



Brownish, orange and reddish kinds were called distinct- 

 ively hyacinths (topazes and garnets were sometimes called 

 the same\ 



